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Subject: misc.kids FAQ on Childhood Vaccinations, Part 2/4

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Archive-name: misc-kids/vaccinations/part2 Posting-Frequency: monthly Last-Modified: October 23, 1999
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D Section 3. Specific vaccines ---------------------------------------------------------------------------= ---- Section 3a. DTP (diptheria, pertussis, and tetanus) and DT [Last updated October 2. 1999.]=20 Q3a.1 What is diptheria, and what are the risks of the disease?=20 Diptheria is a contagious disease affecting the nose, throat, and skin. Com= plications include paralysis (about 20% of patients) and heart damage (about 50%) (Pantell, Fries, and Vickery). The Merck manua= l has a very long list of complications, mostly involving the heart, and says that complications are likely if antitoxin is= n't administered properly. The death rate was 35% before antitoxin was available, and is now 10% (Harrison).=20 Q3a.2 How common was diptheria before routine vaccination, and how common i= s it now?=20 In 1900, there were 40.3 deaths per 100,000 population from diptheria in th= e US. There was a sharp decline in the number of deaths per 100,000 both before and after routine vaccination was instituted= in the 1940s, and in 1990 there were 4 cases of diptheria reported in the US. (_Historical Statistics of the United States,= Colonial Times to 1970_ and _Statistical Abstracts of the United States_.=20 In Europe, there were large diptheria epidemics during and after World War = II, with an estimated one million cases and 50 000 deaths in 1943 (source: WHO web page on diptheria, written March 1998, http://www.who.org/gpv-dvacc/diseases/diphtheria_dis.htm). More recently, t= here have been large epidemics in Russia and the Newly Independent States.=20 Q3a.3 How effective is the diptheria vaccine?=20 "The fatality rate in immunized populations is one-tenth that in the unimmu= nized population. Paralysis is 5 times and 'malignant' disease 15 times less common in immune than in nonimmune individuals." (Har= rison)=20 Q3a.4 How long does the diptheria vaccine last?=20 Ten years.=20 Q3a.5 What is pertussis, and what are the risks of the disease?=20 Pertussis, or whooping cough, is a very contagious disease of the respirato= ry tract. Its attack rate in unvaccinated household contacts is over 90% (PDR) or up to 90 and in some cases 100% (Harrison).= =20 Pertussis is very serious in children under 2, with a mortality rate on abo= ut 1 to 2%. (Merck) "Prior to the availability of a vaccine, pertussis caused as many deaths as all other contagious disease _c= ombined_." (Harrison, p. 607) Complications include various lung complications (The Merck Manual has a long list of the= se), cerebral complications, hemorrage into the brain, eyes, skin, and mucuous membranes. In addition to killing, it can le= ave surviving infants with lasting lung damage and neurological diseases.=20 The mortality rate is higher in developing countries, partly because childr= en in these countries contract pertussis at a younger age (and mortality is higher at younger ages), and partly due to an associa= tion with protein-energy malnutrition (Galazka). This same article estimated that in the industrialized world, 0.04% of infected = children die from pertussis and complications, usually pneumonia "Among vaccine-preventable diseases, pertussis rivals measles and= neonatal tentanus in importance and severity in young children in developing countries and is third only to measles and neo= natal tetanus as a cause of death. It is estimated that pertussis is still causing some 340,000 deaths of children in the world eac= h year." (Galazka)=20 Q3a.6 How common was pertussis before routine vaccination, and how common i= s it now?=20 [Note: This section may be outdated, since the introduction of the new acel= lular vaccine has caused changed in vaccination schedules and vaccination coverage. More recent information on internationa= l vaccine schedules and disease incidence may be found at http://www.who.org.)=20 "Since immunization against pertussis (whooping cough) became widespread, t= he number of reported cases and associated mortality declined from about 120,000 cases and 1,100 deaths in 1950, to an= annual rate of about 3,500 cases and 10 fatalities in recent years." (PDR) For unknown reasons, there has been an i= ncrease in the US recently. "Over 6000 cases of pertussis were reported in the U.S. in 1993, the highest number in 25 years= ." (N Engl J Med 1994 Jul 7; 331:16-21, summarized in Journal Watch for July 22, 1994.) There is also a recent repo= rt (MMWR Nov 11, p. 807) of a strain of pertussis resistant to erythromycin.=20 In some other countries, pertussis is more common (most of the following in= formation is taken from Galazka). "Before the introduction of widespread immunization of young children with pertussis va= ccine, the incidence rates in Europe and the United States were very high. The reported rates per 100,000 population ranged fro= m 200-300 in England and Wales and Sweden, to more than 1,000 in Denmark and Norway." (Galazka) Annual incidence in th= e US and Canada before the introduction of pertussis vaccine in the 1940s ranged from 98 to 210 per 100,000 population= . After the introduction and widespread use of DTP vaccine, incidence declined dramatically in most countries, and this tr= end continued for about 20 years. For example, in England and Wales, more than 150,000 cases of pertussis were reported a yea= r in the 1950s; by 1973, when vaccine acceptance was over 80%, only about 2,400 cases were reported.=20 However, in the late 1970s and the 1980s, different trends began to appear = in different European countries. In one group of countries, reported incidence is between 10 and >100 per 100,000. This grou= p includes Sweden and Italy, which don't routinely give pertussis vaccine to infants. It also includes Germany, the = former USSR, Ireland, Spain, and the United Kingdom, where infants are routinely vaccinated, but coverage is less than = 80%. In Denmark, incidence is high despite high coverage, but Denmark uses a different vaccination schedule from the other = countries. Countries with a moderate reported incidence (between 1 and 10 per 100,000) include Austria, Finland, Greece, = Israel, Norway, the Netherlands, Portugal, Romania, and Yugoslavia. Countries with a low incidence (less than 1 per 10= 0,000) include Hungary, Switzerland, Bulgaria, Czechoslovakia, Poland, and Turkey.=20 Q3a.7 How effective is the whole cell pertussis vaccine?=20 It's one of the less effective childhood vaccinations. The PDR estimates it= s effectiveness at 70-80%. It's effectiveness rating depends on the severity of the cases of pertussis being observed. One study= of 1797 households found the vaccine to be 64% effective against a mild cough, 81% effective against a paroxysmal cough, a= nd 95% effective against severe clinical illness. "Requiring laboratory confirmation improved efficacy to 95 to 98% for cultu= re-positive children and to 77% to 95% for culture- or serology-confirmed cases, depending on disease severity. Vaccin= e efficacy for typical paroxysmal cough increased from 44% for one diptheria, tetanus, and pertussis vaccine to 80% for four = or more doses." (Onorato, Wassilak, and Meade) The variation in estimates of efficacy may be because the more severe cases= were more likely to actually be pertussis, or it may be that the vaccine protects better against severe pertussis than against a= mild form of the disease. Note: these effectiveness ratings are for the older, whole cell pertussis vaccine. For information on= the effectiveness of the newer, acellular vaccines, which is generally comparable to that of the older whole cell vaccines, see= below.=20 Q3a.8 How long does the pertussis vaccine last?=20 It doesn't. According to _Harrison's Internal Medicine_, "the protection ..= . is transient, with minimal resistance being evident a decade later." However, the critical years for pertussis immunity are when = a child is young; the disease is not dangerous for adults. With introduction of the new, less reactogenic acellular vaccine, i= t is possible that boosters may eventually be given to adults. (This estimate is for the older, whole cell vaccine, but the newer = acellular vaccine is apparently at least as durable as the whole cell one was.)=20 Q3a.9 What is tetanus, and what are the risks of the disease?=20 Tetanus is very dangerous. Even with antibiotics, mortality can be 40% or h= igher (Pantell, Fries, and Vickery, Harrison). Tetanus bacteria and its spores are everywhere. Because tetanus is so ubiqu= itous, the only way to counter it is widespread vaccination.=20 ************************************************************************* From=20J Thompson (jet14@columbia.edu): The tetanus vaccine is actually against the tetanus toxin (a protein called tetanospasmin), rather than the bacterium alone. The bacterium doesn't really do much of significance, but the toxin it secretes can cause muscular spasms. Thus, antibiotic therapy is rather pointless in preventing the spasms, but it is given anyway. The administration of antitoxin (passiv= e immunity) is helpful. (see Harrison's, 13th ed., p. 635) The vaccine consists of what is called "tetanus toxoid," which is simpl= y a purified version of the toxin, which has been treated to render it ineffective as a toxin (but still immunogenic). ************************************************************************* Q3a.10 How common was tetanus before routine vaccination, and how common is= it now?=20 300,000 to 500,000 cases are reported worldwide, with a mortality of about = 45%. In the US, there are about 100 cases a year, with a mortality of 40-60% (Harrison).=20 Q3a.11 How effective is the tetanus vaccine?=20 According to Taking Care of Your Child, "Tetanus is one of our best immuniz= ations.... Of all the vaccines available, tetanus comes closest to 100 percent effectiveness after the initial series of shot= s."=20 Q3a.12 How long does the tetanus vaccine last?=20 Generally ten years. In the case of a really dirty wound, a booster is reco= mmended if the person hasn't been vaccinated for tetanus within the last five years.=20 Q3a.13 What are some of the risks of the DTP vaccine?=20 DTP, particularly in its earlier form (with the whole cell pertussis compon= ent) is probably the most controversial of the childhood vaccines, because of risks associated with its pertussis componen= t. Anecdotal evidence has linked the vaccine with a variety of problems, including convulsions, physical collapse, brain damage= and SIDS. Supporters of the vaccine have argued that these problems are common in any case at the age at which children are= vaccinated for pertussis, and therefore are not necessarily effects of the vaccine.=20 The association between DTP and SIDS has not been confirmed by further stud= y (see Q1.5 for a study which found the evidence to be against such an association). The story on brain damage is s= omewhat different. Criticism of the pertussis vaccine received some confirmation in 1976, when a large British study of all child= ren 2 to 36 months old in Britain found that 1 in 310,000 doses resulted in permanent brain damage.=20 Critics argue that the rate of complications from the pertussis vaccine is = too high, and the effectiveness too low. Some argue that the decline in pertussis cases in this century has been an effect more= of improved sanitation than of the pertussis vaccine. The side effects of this vaccine have inspired groups critical of vaccinati= on in several countries, including the US, where the group Dissatisfied Parents Together (DPT) has lobbied Congress for changes = to laws about vaccination and set up its own vaccine information center.=20 Supporters of the pertussis vaccine differ in their response to the British= study which linked pertussis to brain damage. Some say that further analysis indicates that a link between the vaccine and bra= in damage is not so clear. "Meticulous reexamination of the data from this study led to the conclusion that the preliminary resu= lts were due to a systematic bias that favored finding an association between the vaccine and serious neurological sequelae. In fact,= there was no valid evidence from the study that the vaccine was associated with permanent neurological damage." (Shapiro)=20 Some smaller studies done since the British study didn't find a connection = between DTP vaccine and neurological damage, and a new study was just published in the Journal of the American Medical Assoc= iation which finds no increased risk of serious neurological illness. I haven't seen the article yet, so my information com= es from the January 11, 1994 San Jose Mercury (from the New York Times news service), which reports that the study is in the cu= rrent (as of 1/11/94) issue of JAMA. According to the article, "The federally financed study, the largest of its kind in the = United States, involved 218,000 children up to 24 months old in Oregon and Washington who were studied for a one-year period, beginn= ing Aug. 1, 1987." However, the study is also described as "not intended to give a definitive answer to the question of w= hether whooping cough vaccine causes neurological illness."=20 Others do not dispute the 1976 British study, but argue that a 1 in 310,000= risk of brain damage is still much smaller than the risk of actually getting pertussis. Supporters agree that it is important t= o maintain high vaccination levels against pertussis, lest we see a resurgence in the disease. In Great Britain, Japan, and Sweden, th= ere were sharp increases in the number of cases of pertussis when vaccination levels fell. Routine use was discontinued in Swe= den as a result of reports of side effects, while acceptance in Great Britain declined to 30% (Harrison), and vaccination dec= lined in Japan as well. "Within two years, one hundred thousand cases (with twenty-eight deaths) appeared in Great Britain= and thirteen thousand cases (with forty-one deaths) in Japan. Even in the US, the disease has by no means been wiped ou= t; there are still about fifteen hundred to two thousand cases (with four to ten deaths) each year. That is why virtually a= ll health care authorities recommend that we keep using this vaccine." (UC Berkeley)=20 ACIP considered the available data on brain damage in 1991, and concluded t= hat "Subsequent studies have failed to provide evidence to support a causal relation between DTP vaccination and either se= rious acute neurologic illness or permanent neurologic injury." It further noted that "The risk estimate from the NCES = study of 1:330,000 for brain damage should no longer be considered valid on the basis of continuing analysis of the NCES = and other studies." (Staff, Diptheria, tetanus, and pertussis: recommendations for vaccine use and other preventive measures, i= n Recommendations of the Advisory Committee on Immunization Practices (ACIP). Aug 8, 1991, CDC: Atlanta. p. 1-21.)=20 Known and non-controversial (i.e. everyone agrees that they occur) side eff= ects of DTP vaccine include redness and tenderness at the injection site, fever, drowsiness, fretfulness, vomiting,= and convulsions. (A vaccine information pamphlet from Kaiser gave the frequency as being 1 in 100 to 1 in 1000 for crying without= stopping for three hours or longer, a temperature of 105 F or greater, or an unusual, high-pitched cry, and 1 in 1,750 for co= nvulsions, generally from high fever, or shock collapse. I didn't see any frequencies in the PDR, other than describing th= ese side effects as rare.) It is a good idea to give acetaminophen to children being vaccinated for pertussis, to reduce the cha= nce of fever and febrile convulsions.=20 From=20Mike Dedek: ************************************************************************* American Journal of Diseases of Children 1992; 146: 173-176, February 1992,= =20 "Pertussis outbreaks in Groups Claiming Religious Exemptions to Vaccination= s",=20 Etkind, Lett, et. al.: 2% non-vaccinated students are monitored> : Key measures in preventing pertussis are immunization and judicious use of prophylactic antibiotics. Pertussis can be prevented in children by immunization. Unfortunately, controversy over the safety of the pertussis vaccine has reduced acceptance. Highly publicized accounts of reactions t= o the vaccine and a dramatic increase in the number of malpractice lawsuits have= made physicians and parents wary of using the diphtheria-tetanus toxoid and per= tussis vaccine. {n4-n6} This publicity may have caused overinterpretation of the guidelines for medical contraindications. {n7} However, this overinterpret= ation creates its own risk for malpractice if a child given an inappropriate med= ical contraindication suffers damage due to disease. ************************************************************************* Q3a.14 Did SIDS disappear in Japan after the Japanese changed their pertuss= is vaccination policy in 1975?=20 This claim is examined at length by Lon Morgan, DC,DABCO in his Web site "A= summary of JAPAN, SIDS, and PERTUSSIS IMMUNIZATION" at http://fp1.cyberhighway.net/~lmorgan/fearmongers= /japan_sids.htm. It turns out that what went away, in 1975, when Japan increased the age at which it administered t= he first dose of the vaccine from three months to two years, was *claims of vaccine injuries* for SIDS. Japan had a compensat= ion system for vaccine injuries, in which claims were to be paid unless other causes were clearly provable. Under this syste= m, 11 claims were paid for what was termed Sudden Death, between 1970-1975 (this out of 25-30 million doses of pertuss= is vaccine). After the vaccination age was raised, no further claims were paid for Sudden Death related to vaccination= . Since SIDS occurs before 12 months of age, any cases of SIDS can not be attributed to a vaccine which is given starting at= 24 months.=20 Japan has, however, kept statistics for SIDS, and these statistics showed t= he numbers of SIDS cases *increasing*, rather than decreasing, at the time that the age of the first pertussis vaccination was= raised. Though the delay in age for the first pertussis vaccination did not reduce the incidence of SIDS, it did result in a huge i= ncrease in pertussis cases, peaking at 13,105 cases and 41 deaths by 1979. For more details, and references, see Lon Morgan's s= ite.=20 As a side note, recent vaccination rates for Japan, as listed in http://www= .who.int/gpv-surv/country/japan.html, were, in 1996, 98% for polio, 100% for diptheria, pertussis, and tetanus, and 94% for meas= les; the coverage for BCG in 1993 was 91%.=20 Q3a.15 When is the DTP vaccine contraindicated?=20 Hypersensitivity to a vaccine component, including thimerosal, a mercury de= rivative. Defer vaccination in case of fever or acute infection (but not nececcarily for a mild cold without a fever). A history = of convulsions is generally a contraindication to pertussis vaccination, but "The ACIP and AAP recognize certain circumstance= s in which children with stable central nervous system disorders, including well-controlled seizures or satisfactorily expl= ained single seizures, may receive pertussis vaccine. The ACIP and AAP do not consider a family history of seizures to be a contr= aindication to pertussis vaccine." (PDR)=20 The following reactions to a previous dose are contraindications: An immedi= ate anapylactic reaction. Encephalopathy occuring within 7 days following DTP vaccination. Precautions include a fever of >= =3D 40.5 C (105 F) within 48 hours, collapse of shocklike state within 48 hours, persistent inconsolable crying for more th= an 3 hours within 48 hours, convulsions with or without fever within 3 days. (These latter are precautions rather than cont= raindications, because there might be circumstances, such as a pertussis epidemic, where you would still want to give the vaccin= e.)=20 Pertussis vaccine should not be given to anyone over seven years old (this = may change, in time, with the new acellular vaccine, but further study is needed first).=20 Vaccine components capable of causing adverse reactions: for diptheria, thi= merosal and toxoid; for tetanus, thimerosal and toxoid; for pertussis, bacterial components (Travel Medicine Advisor).=20 (Note: There is currently, as of 1999, a move toward replacing thimerosal i= n vaccines, so the reference to thimerosal here may shortly be out of date.)=20 Q3a.16 What are the advantages and disadvantages of the new acellular pertu= ssis vaccine?=20 The big advantage is that the acellular vaccine has fewer side effects. The= FDA initially held off on approving it for the earlier shots (while approving it for the fourth and fifth shots), mainly due to re= maining uncertainty as to whether it is as effective as the whole cell vaccine. Reports from Japan indicated that it is, but a Swedish = clinical trial indicated efficacy of 59% for one, and 64% for the other acellular vaccine. However, even this trial did show >90%= efficacy against severe pertussis. (Shapiro) More recent results in Sweden and Italy indicate it is both safe and effective. = On July 31, 1996, the FDA licensed one acellular pertussis vaccine for the inital three shots, and more followed. The Americ= an Association of Pediatrics has issued guidelines for the use of the new vaccine, which can be found at their web page, http://ww= w.aap.org.=20 As of 7/14/95, results were available from two large European studies, invo= lving 9,829 infants in Sweden and 15,601 infants in Italy. The National Institute of Allergy and Infectious Disease (in the US)= reported that "three similar experimental vaccines effectively immunized 84% to 85% of the children in the trials, while resul= ting in fewer side effects than current, widely used versions." (Wall Street Journal, 7/14/95, p. A7A) A surprising result of th= e studies was that whole cell pertussis vaccine efficacy rates were lower than usual: "conventional vaccines provided prote= ction for just 36% of children in Italy and 48% in Sweden. In the US the conventional vaccine proves effective in 70% to 95% o= f the children who are vaccinated." Officials suggested that infants in these studies might have had a higher intensity o= f exposure to the bacteria due to the lack of widespread vaccination in those countries, and that might explain the lower= efficacy. A fourth acellular vaccine provided protection in 58% of the cases. The high efficacy and low side effects show= n for the acellular pertussis vaccine in these studies will likely lead to requests that the FDA also approve the acellular vaccin= e for the earlier pertusis shots. More information on recent study results can be found in NEJM, Vol. 333, Number 16, Oct. 19, 19= 95 (B. Trollfors and others).=20 From=20Mike Dedek: This next one indicates there's a better vaccine that may soon become available [Note: this vaccine is now available, and recommended for all doses in the US and some industrialized countries]: ************************************************************************* In Pediatrics 1992; 89; 882-887, May 1992, "Acellular Pertussis Vaccination of 2-Month Old Infants in the United States", Pichichero, Francis, et. at.: ABSTRACT: This is the first study in children from the United States that evaluates the immunogenicity of and adverse reactions to the Connaught/Bike= n two-component acellular pertussis vaccine compared with whole-cell pertu= ssis vaccine when given as a primary immunization series at 2, 4, and 6 months o= f age. Three hundred eighty infants were studied; 285 received acellular diphtheria-tetanus toxoids- pertussis (DTP (ADTP)) and 95 received whole-c= ell DTP (WDTP). Following the third dose, ADTP vaccination produced higher ant= ibody responses than WDTP to lymphocytosis-promoting factor (enzyme-linked immunosorbent assay IgG geometric mean titer (GMT) =3D 131 vs 9 and Chinese hamster ovary cell assay GMT =3D 273 vs 16) and to filamentous hemagglutini= n (IgG GMT =3D 73 vs 10) (all P < .0001). Agglutinin responses were higher in WDT= P compared with ADTP recipients (GMT =3D 50 vs 37; P =3D .02). Local reactio= ns were fewer for all three doses following ADTP vaccination. Fever, irritability, drowsiness, anorexia, vomiting, and unusual crying all occurred less freque= ntly in ADTP compared with WDTP recipients for one or more of the three doses. = We conclude that this two-component ADTP vaccine when given as a primary serie= s produces greater immunogenicity and fewer adverse effects than the currentl= y licensed WDTP vaccine. ...A large case-control study in Britain (National Childhood Encephalopathy Study) estimated that permane= nt neurologic deficits may occur after its administration in 1 in 310000 doses of WDTP. However, a reanalysis of this and similar studies recently has le= d=20 to the widely held conclusion that a causal association between WDTP vaccin= ation and permanent brain damage has not been demonstrated.... ************************************************************************* Public Health Rep 1992; 107: 365-366, May 1992/June 1992, "FDA Approves New Whooping Cough Vaccine" The Food and Drug Administration (FDA) has licensed a new whooping co= ugh vaccine that may cause fewer side effects in children. The new vaccine is being approved at this time only for the fourth an= d fifth shots. The current vaccine will continue to be used for the first t= hree shots. Additional research has been undertaken to ascertain whether it wi= ll be effective for preventing pertussis when used for primary inmunization --= the first three shots -- in infants. The new vaccine is acellular, meaning that it is made from only part o= f the pertussis organism, as opposed to the whole organism from which the curre= nt vaccine is derived. Whooping cough ( pertussis) is a highly contagious disease. As many as= 90 percent of nonimmune household contacts acquire the infection. Since rout= ine immunization against pertussis became common in the United States, the n= umber of reported cases of disease and deaths from it has declined from about 12= 0,000 cases with 1,100 deaths in 1950 to an annual average in recent years of ab= out 3,500 cases with 10 fatalities. The new vaccine appears to be as effective in older children as the cu= rrent vaccine and to cause fewer adverse reactions. It has been widely used in = Japan -- where it was developed -- with apparent success in children older than = 2 years. It will be combined with diphtheria and tetanus toxoids (DTP) and = sold under the brand name Acel-Imune. Gerald Quinnan, MD, acting director of FDA's Center for Biologics, where= the vaccine was evaluated and licensed, said that the availability of an acell= ular vaccine is a significant step forward in infectious disease control. The most common adverse reactions seen in clinical trials of the acellula= r pertussis vaccine included tenderness, redness, and swelling at the injec= tion site, fever, drowsiness, fretfulness, and vomiting. The new pertussis vaccine component is produced by Takeda Chemical Industries Ltd. of Osaka, Japan, and is combined with diphtheria and tetan= us toxoids manufactured by Lederle Laboratories of Wayne, NJ. Lederle will a= lso distribute the product in the United States. The vaccine is administered = by injection. The approval of the new vaccine comes at a time when the Federal Govern= ment is emphasizing early childhood immunizations in the wake of the largest rep= orted measles outbreak in the nation in 20 years -- with more than 27,600 cases a= nd 89 deaths reported in 1990. The aim is to reach a goal of full immunization for 90 percent of childre= n by the time they are 2 years old. ************************************************************************* As of September 1999, results are available from still more studies. Since = 1991, seven studies in Europe and Africa evaluated the efficacy of eight DTaP vaccines given to infants. The vaccines were by = different manufacturers, with varying number and quantity of antigens. Number of doses varied (three in some, four in others= ), as did other aspects of the study design, such as the case definition for pertussis and the laboratory method used to confirm= the diagnosis. For this reason, the studies can't be compared directly, but within the individual studies, the efficacy of whole= cell vaccine can be compared with the efficacy of acellular. Acellular was within the range expected for whole cell. Estimate= s of efficacy ranged from 59% to 89%. More serious adverse effects (fever over 105 F, persistent crying for more than three ho= urs, hypotonic hyporesponsive episodes, and seizures) happened less often with acellular. Really rare adverse events (e= ncephalopathy and anaphylactic shock) were too rare to show up in these studies. Acellular pertussis vaccines have also been us= ed routinely since 1981 in Japan.=20 Despite the acellular vaccine's comparable efficacy and few adverse reactio= ns, the whole cell pertussis vaccine retains one advantage which ensures some continued use. It is cheaper, and more organiz= ations know how to make it In developing countries, where pertussis is a major killer, and money for vaccines in sho= rt supply, it is not clear that the advantages of the acellular vaccine justify the additional cost.=20 Q3a.17 What are some of the risks of the DT (diptheria and tetanus) vaccine= ?=20 Most of the risk in the DTP vaccine comes from its pertussis component; the= diptheria and tetanus vaccines are quite safe. Reactions to the diptheria vaccine are quite rare. Most reactions are local= , limited to swelling at the injection site. The same is true of the tetanus shot. "Severe local reactions can occur if too many sho= ts are received; this phenomenon was frequently seen in military recruits who received unneeded immunizations." (Pantell, Fries,= and Vickery)=20 Q3a.18 When is the DT vaccine contraindicated?=20 Should be avoided during the first trimester of pregnancy. People who have = had a reaction (which is very rare) should avoid it.=20 Vaccine components capable of causing adverse reactions: for diptheria, thi= merosal and toxoid; for tetanus, thimerosal and toxoid (Travel Medicine Advisor).=20 (Note: There is currently, as of 1999, a move toward replacing thimerosal i= n vaccines, so the reference to thimerosal here may shortly be out of date.)=20 Q3a.19 Under what circumstances is tetanus toxoid given to pregnant women?= =20 Tetanus toxoid is given to pregnant women in countries where there is a hig= h risk of neonatal tetanus (due to factors which enhance the risk of cord contamination in these countries).=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D Section 3b. Polio [This section last updated September 19, 1999.] Q3b.1 What is polio, and what are the risks of the disease?=20 Polio is a contagious viral disease which crippled tens of thousands in the= 1950s, and killed more than a thousand a year. Because it is a mild gastrointestinal illness in young children and a serio= us paralytic illness in older people, it had an unusual epidemiology, with more cases of paralytic polio turning up in wealthy area= s and as sanitation improved. 80-90% of cases of polio are the minor illness; the rest are paralytic poliomyelitis. In paral= ytic poliomyelitis, < 25% suffer permanent severe disability, about 25% have mild disabilities, and > 50% recover with no res= idual paralysis. Mortality is 1 to 4%. "Recently, a post poliomyelitis syndrome has been described, characterized by muscle fat= igue and decreased endurance... The syndrome occurs many years after an attack of paralytic poliomyelitis..." (Merck).= =20 Q3b.2 How effective is the polio vaccine?=20 The Merck Manual and the Physician's Desk Reference give its effectiveness = as 95%. An article in a WHO publication (Hull and Ward) estimates effectiveness at 80%. (As with other WHO estimates, the= lower effectiveness rating reflects an estimate of effectiveness in the field in a variety of countries, including countrie= s in the Third World. Polio vaccine effectiveness can deteriorate if it is exposed to too much heat, which can happen in vaccinat= ion programs in some countries.)=20 Q3b.3 How long does the polio vaccine last?=20 It provides lifelong immunity.=20 Q3b.4 What is the difference between oral polio vaccine (OPV) and inactivat= ed polio vaccine (IPV)?=20 Oral polio vaccine provides better immunity, and was until recently usually= the recommended form, "because induces intestinal immunity, is simple to administer, is well accepted by patients, results in= immunization of some contacts of vaccinated persons, and has a record of having essentially eliminated disease associated with w= ild poliovirus in this country." (PDR) However, it carries a small risk of paralysis (see the answer to the next question for = details).=20 Recently, with increased progress in worldwide eradication of polio, both A= CIP and AAP have changed their recommendation to IPV for all shots. OPV remains the vaccine of choice for countries where= polio is still endemic, and for people who will be shortly travelling to such countries.=20 Q3b.5 I've heard that it is possible to contract polio from handling the di= apers of recently immunized infants. How long after receiving the vaccine does the child's excrement continue to contain the vi= rus?=20 ************************************************************************* From=20Caren Feldman: > Speaking of this, I know there has been mention in the past of contractin= g > polio from handling diapers of recently immunized infants. Does anyone > know how long after receiving the vaccine the child's excrement continues= to > contain the virus? The reason I ask is because sean got his polio booste= r > and Rachel has only received the first vaccine in the series. The doctor= 's > office said she wain no danger of contracting poliofrom him since they do= n't > come in contact with each other *that* closely. However, I have to be ex= tra > careful after helping Sean clean up (he needs help sometimes) or handling= his > underwear to make sure I wash my hands thoroughly. So, how long until I > can stop being paranoid about remembering to wash my hands after handling > the laundry? (I forgot to ask) >=20 The short answer is 6 weeks. But since you brought up the subject...here's = what I fond out about polio immunizations: When I had read one poster's response that the live polio virus from feces was actually weakened virus that would in fact help immunize unimmunized ki= ds they'd come in contact with it, naturally I didn't believe it. Well, not at first. But I had enough doubts of my disbelief to start asking around, and = came up with some (at least to me) little known facts about polio and polio immunizations. I am presenting it to misc.kids for everyone's edification. Indeed, live virus from a recently immunized child's feces is weakened viru= s that health officials actually hope unimmunized kids come in contact with = to provide them with individual immunity and the general population with "herd= " immunity. Now here's the tricky part. One of the attenuated strains used to make the vaccine has a very low but existing back mutation rate, back to the "wild type", i.e. back to "regular" polio. If the weakened virus the child has be= en given mutates back to wild-type polio, any adult with no immunity to it (or an immunized adult for whom the immunization series did not "take") is potentially at risk for full blown polio. Of course, people with weak immun= e systems may be at risk even from weakened virus. Steroid use may also caus= e the immune system to weaken (besides the usual anti-rejection drugs, HIV, leukemia) and thus increase susceptibility for contracting the virus. Polio in young children manifests itself as a mild gastrointestinal ailment= . Polio in older children and adults starts as a mild gastroenteritis but wit= h complications that may lead to paralysis. Before the advent of improved pub= lic sanitation, most young children were exposed to and probably contracted the polio virus, so by adulthood, chances were everyone had immunity to it. It was only when public sanitation improved to where exposure to the virus was delayed until later childhood that polio epidemics became prevelant. Polio outbreaks in the US were less frequent among poor children than among more= =20 affluent families. The CDC estimates the chances of getting polio from a first immunization (I presume this means gastroenteritis symptoms in babies, not paralytic polio) is one in half million. The chances of getting polio from subsequent immunizations is 1 in 12 million. I assume the chances of secondarily contracting polio from feces are even rarer. These rare cases probably account for the supermarket tabloid (not to menti= on "60 Minutes") stories of adults catching polio from recently immunized kids who'd been given oral vaccine. For those in the US, you will be glad to hear that a federal compensation program exists, called the National Vaccin= e Injury Compensation Program, to help those stricken with paralytic polio as= a result of coming into contact with a recipient of the oral polio vaccine. Thanks go to two posters on sci.med for answering my questions regarding th= is subject. ************************************************************************* The 1993 Physician's Desk Reference confirms Caren Feldman's account, with = two small modifications. First, it gives the time when the virus is shed as 6-8 weeks, rather than six. Second, the CDC estim= ates which she gives are the estimates for cases of paralysis in *both* vaccine recipients and contacts of vaccine recipients c= ombined, not for recipients alone.=20 Q3b.6 What are some other risks of the polio vaccine?=20 A small risk of anaphylactic shock.=20 Q3b.7 When is the polio vaccine contraindicated?=20 Because of the small risk of paralytic polio in recipients and contact of r= ecipients of OPV, it should not be given to anyone who is immune-compromised or who has immune-compromised family members. (The PD= R has a really long list of immune deficiencies involved, which you can check if you think anyone in your fami= ly falls in this category.) In these cases, IPV should be given instead. IPV is also recommended for adults who are at risk for po= lio (such as unvaccinated adults travelling to an area where polio is endemic). Both vaccines are contraindicated for people = with an anaphylactic allergy to neomycin or streptomycin.=20 Vaccine components capable of causing adverse reactions: for both OPV and I= PV, streptomycin, neomycin, and phenol red; for IPV, animal protein, formaldehyde, and polymyxin B (Travel Medicine Adv= isor).=20 Q3b.8 Isn't it true that wild polio has been eliminated in the US?=20 From=20Mike Dedek: ************************************************************************* >From The Reuter Library Report, 2/26/93, "U.N. Warns on need for Polio=20 Immunisation" copyright 1993 Reuters: The last outbreak of polio took place in the Netherlands 15 years ago. T= he virus was carried to Canada and the United States by infected people visit= ing their relatives, the WHO said. This caused the United States' last polio outbreak which hit the Amish community in the state of Pennsylvania in 1= 979. ************************************************************************* >From The [London] Independent, 2/9/93, pg. 12, "Why child vaccines may be = a shot in the dark", by Tessa Thomas: After numerous cases in which the ''live'' oral polio vaccination was found to have caused the disease, the American government is considering reintroducing the inactivated injectable version. In the UK, the Departmen= t of Health advocates the live version on the basis that it deactivates any wil= d polio virus that reaches the gut, preventing it being excreted into the community, thus conferring community protection. The injectable vaccine ac= ts only on the bloodstream, protecting the individual but not breaking the ch= ain of infection. Lobbying by the Association of Parents of Vaccine Damaged Child= ren has prompted an acknowledgement by Virginia Bottomley, the Secretary of St= ate for Health, that the live vaccine is responsible for 50 per cent of recent= new cases of polio. Between 1978 and 1991 there were 42 cases of polio, 18 = of which followed vaccination and nine of which followed infection through co= ntact with the vaccinated child. ************************************************************************* The Atlanta Journal and Constitution, 12/19/92, "Cases in Netherlands put Americas at risk for polio", by Steve Sternberg, Section E; pg. 1 The last polio case in the Americas emerged on Aug. 23, 1991 in the remot= e Peruvian highlands village of Pichinaki... ************************************************************************* UPI 12/10/92: Except for a few rare vaccine-associated cases, there have been no cas= es of polio in the United States since 1986 when there was one imported ca= se. The current vaccine, Sutter said, is close to 100 percent effective in preventing the disease. ************************************************************************* MMWR's Summary of Notifiable Diseases, United States, 1997 (MMWR, November = 20, 1998 / 46(54);1-87) reports that "Since 1980, a total of 147 cases have been reported, of which 139 were ass= ociated with the use of OPV. The last imported case was reported in 1993."=20 Q3b.9 Why are we still vaccinating for polio, then?=20 The AAP and ACIP continue to recommend vaccination for polio for several re= asons. First, the risk of the disease is much higher than the risk of the vaccine. Second, though there is no wild polio = in the US *now*, with high levels of vaccination, there is still polio elsewhere in the world. 148,000 cases were reported to WHO i= n 1990. China reported 5,065 cases. The USSR reported 337 cases. India reported 7,340. (Hull and Ward) There have been s= everal outbreaks of polio in countries 2 or more years after the last reported case of polio. Importation from polio endemic= countries has led to outbreaks in Oman (1988-89 and 1993), Jordan (1991-92), Malaysia (1992), and the Netherlands (1992-93)= (MMWR, reported in HICNet Medical News on 15 August 1994). Wild poliovirus type 3 was isolated during January= -February 1993 among members of a religious community objecting to vaccination in Canada (although no actual cases of p= arlytic polio occurred in Canada at this time). There is a concern that if levels of vaccination were reduced in the US, po= lio could be reintroduced, and we could see polio epidemics here again.=20 Encouraged by the worldwide elimination of smallpox, WHO, in 1988, set a go= al of eradicating polio from the world by 2000. Since then, the number of cases in the world has declined dramatically (29,= 916 in 1989 and 16,435 in 1990), and the number of countries reporting 0 cases has increased (74 countries in 1985 and 116 = countries in 1990). As of 1993, the number of cases worldwide has falled to 9714, and nearly 70 percent of all countries = reported no cases. (Progress toward global eradication of poliomyelitis, 1988-1993. MMWR 1994 Jul 15; 43:499-503. Summ= arized in Journal Watch Summaries for July 22, 1994.) As of 1999, WHO reports still further progress, "In 1988, virus = circulated widely on all continents except Australia. By 1998, the Americas were polio-free (certification of eradication in 1994= ), transmission has been interrupted in the Western Pacific Region of WHO, including China, and in the European Region, except = for a small focus in south-east Turkey. As shown below, only three major foci of transmission remain: South Asia (Afghanista= n, Pakistan, India), West Africa (mainly Nigeria) and Central Africa (mainly Democratic Republic of Congo)." So another facto= r in the decision to continue vaccinating for polio is the hope that it can be eliminated for good.=20 After much debate, the US has switched to IPV instead of OPV (IPV being les= s effective, but lower in side effects). The decision at first was to continue with OPV because it has been so successfu= l, the rate of side effects is still considered very low, and because of various advantages in producing immunity (see above). Accord= ing to the 1993 PDR, "The choice of OPV as the preferred poliovirus vaccine for primary administration to children in = the United States has been made by the ACIP, the Committee on Infectious Diseases of the American Academy of Pediatrics, and= a special expert committee of the Institute of Medicine, National Academy of Sciences." In 1995, though, that decision was= changed, and the injected vaccine became recommended for the first two polio shots. As progress toward worldwide pol= io eradication continued, and as the change in the vaccination schedule (from an oral to an injected form) did not result = in any decline in vaccination coverage, ACIP and AAP are now recommending IPV for all shots.=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D Section 3c. MMR (measles, mumps, and rubella) [This section last updated on October 23, 1999.]=20 Q3c.1 What is measles, and what are the risks of the disease?=20 Measles is one of the most contagious infectious diseases. "A child can cat= ch measles by breathing the air in a doctor's waiting room two hours after an infected child has left." (Fettner) 90% of suscepti= ble household contacts get the disease (Harrison). Measles spreads very rapidly in unexposed populations. In 1951, it was intr= oduced to Greenland by a recently arriaved visitor who went to a dance as he was coming down with it, and in three months it s= pread to more than 4000 cases and 72 deaths. The attack rate was 999 cases per 1000 people. In 1875, measles was introdu= ced to Fiji and killed 30 percent of the population (Smith).=20 In areas where it was endemic, before the measles vaccine, measles epidemic= s used to occur at regular intervals of two to three years, usually in the spring, with small local outbreaks in intervening yea= rs. Mortality is low in healthy, well-nourished children unless complications ensue (Merck), but nevertheless there were 400 deaths = a year before an improved measles vaccine was introduced in 1966 (Pantell, Fries, and Vickery). Complications include bra= in infection, pneumonia, convulsions, blindness, various bacterial infections, encephalitis, and SSPE (a fatal complication = which can occur years after a person has had measles). Pregnant women who get measles have a 20% chance of miscarriage.= =20 Worldwide, measles is one of the leading causes of childhood mortality. "Me= asles has been called the greatest killer of children in history." (Clements, Strassburg, Cutts, and Torel) In 1990, "45 million = cases and around 1 million deaths were estimated to occur in developing countries. Thus measles is still responsible for more d= eaths than any other EPI target diseases. The true number dying as a result of measles may be twice the estimated 1 million if= the recently documented delayed effect of the disease is taken into account." (Ibid.) Mortality is higher in developing c= ountries due to a difference in the age at which most people catch it (measles is a more dangerous disease in the very young), po= orer nutrition, less availability of treatment for bacterial chest infections, and other environmental factors. However, "Even= in countries with adequate health care and healthy child populations, the complication rate can reach 10%." (Ibid.)=20 More information on the incidence of measles complications is found in the = answer to Q3c.2.=20 Q3c.2 How common was measles before routine vaccination, and how common is = it now?=20 ************************************************************************* From=20Anthony C.: I havent finished reading this thread so pardon if someone else has already posted this information Rates of complications of measles and measles immunization Measles per 10^5 Vaccine per 10^5 Encephalomylelitis 50-400 .1 sspe .5-2.0 .05-.1 Pneumonia 3800-1000 =20 Seizures 500-1000 .02-19 Deaths 10-10000 .01 These statistics are worldwide, hence the variablility in numbers. The higher rates of pneumonia and death represent figures collected from India, Nambia, Nigeria, bangladesh and other countries with developing health care industries. As far as the number of people afflicted with measles in the US Cases Deaths 1963 385,566 364 Inactivated measles type vaccine available 1964 458,093 421 1966 204,136 261 public health administration of vaccine 1967 62,705 81 1968 22,231 24 . .hovers around 20-70,000 . 1977 57,345 15 1978 26,871 11 1979 13,597 6 1980 13,506 11 1981 3,032 2 1982 1,697 2 1983 1,497 4 1984 2,587 1 1985 2,822 4 1986 6,273 2 1987 3,588 2 1988 2,933 not available 1989 16,236 41 1990 26,520 97 iMajor foci of retransmission barring the complete elimination of measles: 1) unimmunized indigent, inner city youngsters. 2) illegal aliens. I hope this is useful. My source is Zinsser microbiology, 20th edition pages 1013-1015, joklik et al. ************************************************************************* As the above table shows, there was a marked increase in measles incidence = in the US from 1989 to 1991. This resulted in more than 50,000 cases including 125 deaths (http://www.immunize.org/nslt.d= /n21/paradx21.htm). Measles has been on the decline again in the US since 1990 (MMWR Feb 4, 1994, p. 57). Colleges enfo= rcing the requirement for a second measles vaccine report fewer measles outbreaks than schools with no requirement (JA= MA, Oct 12, 1994, p. 1127). (Both of these citations from Journal Watch for Jan 15, 1995 - paper edition, or Feb 7, 19= 95 - electronic edition.) During 1998, a provisional total of 100 measles cases was reported to the CDC, making for a record low= , 28% lower than the 138 cases reported in 1997 (MMWR 48(34);749-753, 1999. Centers for Disease Control).=20 Q3c.3 How effective is the measles vaccine?=20 The Merck Manual and the Physician's Desk Reference estimate its effectiven= ess at 95%. This estimate is based on studies of the immunity induced by a series of vaccinations beginning at 15 months. An= other article, estimating the immunity induced in field conditions (including some Third World countries, which may have less= reliable vaccine storage) by a series of injections beginning at 9 months (the injections are started earlier in areas where me= asles is widespread), estimated effectiveness as 85% (Clements, Strassburg, Cutts, and Torel).=20 A recent article in Pediatric News (Imperio. Vaccine-Exempt At Higher Risk = For Measles. Pediatric News 33(9):9, 1999.) reported that "Individuals aged 5-19 years who were not vaccinated due to r= eligious or philosophical exemptions were, on average, 35 times more likely than vaccinated individuals to contract measl= es, according to a population-based, retrospective cohort study."=20 Q3c.4 How long does the measles vaccine last?=20 The Merck Manual describes it as "durable." The PDR says that all of the an= tibody levels induced by MMR have been shown to last up to 11 years without substantial decline, and "continued surveill= ance will be necessary to determine further duration of antibody persistance."=20 Q3c.5 What are some of the risks of the measles vaccine?=20 There is a small chance of complications similar to the complications of me= asles (pneumonia, encephalitis, SSPE). Information on the frequency of these complications is included in the answer to Q3c.2.= There is some risk of anaphylaxis. This risk is low; from the time that VAERS was instituted in 1990 till the publication of Upd= ate: Vaccine Side Effects, Adverse Reactions, Contraindications, and Precautions by ACIP in 1996, >70 million doses of MM= R vaccine had been distributed in the US, and only 33 cases of anaphylactic reactions had been reported to VAERS. It has = been traditionally believed that this risk is mainly for people allergic to eggs or neomycin. However, recent studies indicate t= hat anaphylactic reactions are not associated with egg allergies, but with some other component of the vaccine. There have bee= n some case reports, in the US and Japan, of anaphylactic reactions to the MMR vaccine in people with an anaphylactic se= nsitivity to gelatin.=20 In rare instances, MMR vaccine can cause clinically apparent thrombocytopen= ia within 2 months after vaccination. Passive surveillance systems report an incidence of 1 case per 100,000 doses in Can= ada and France, and 1 per million in the US. Prospective studies have reported a range from 1 in 30,000 in Finland and G= reat Britain to 1 in 40,000 in the US, with a clustering of cases about 2-3 weeks after vaccination.=20 An article in the Feb 28, 1998 Lancet (based on 12 cases) about a possible = association between inflammatory bowel disease, autism, and MMR vaccine (Wakefield et al) raised concerns that the vaccine = might increase the risk of autism. Wakefield and his colleagues did not claim to have actually shown that the vaccine caused= autism, but rather called for further investigation of the question. An accompanying editorial in the same issue of Lancet express= ed concerns about the validity of the study.=20 The article, and the public concern it raised, led to several further inves= tigations of whether such an association existed. A research letter in the May 2, 1998 issue of Lancet reported on a 14-year pr= ospective study, in Finland, of children who had experienced gastrointestinal symptoms after receiving the MMR vaccine. 31 c= hildren (out of 3 million vaccine doses) reported gastrointestinal symptoms; all recovered, and none developed autism. A Work= ing Party on MMR Vaccine of the United Kingdom=92s Committee on Safety of Medicines (1999) examined hundreds of re= ports, collected by lawyers, of autism or Crohn's disease (a gastrointestinal disease) and similar problems, after th= e MMR vaccine, and concluded that there was no causal relationship. A Swedish study (Gillberg and Heijbel 1998) found no d= ifference in the prevalence of autism in children born before the introduction of MMR vaccine in Sweden, and children born af= ter. Wakefield and colleagues did laboratory assays in patients with inflammatory bowel disease (the mechanism which the= y had proposed for autism following the MMR vaccine), and found them negative for measles virus (Chadwick 1998, Duclos = 1998, cited by the CDC at http://www.cdc.gov/nip/vacsafe/vaccinesafety/sideeffects/autism.htm).=20 Finally, a study in the June 12, 1999 issue of Lancet examined children bor= n with autism since 1979 in eight North Thames health districts, to look for changes in incidence or age at diagnosis sinc= e the introduction of MMR vaccination in the UK in 1988. The study found a steady increase in cases of autism, with no sudden = change in the trend after the introduction of the MMR vaccine. Parents most frequently reported first noticing symptoms of au= tism at around the age of 18 months, after the MMR vaccine would have been received, but there was no difference in age at= diagnosis between those vaccinated before and after 18 months and those never vaccinated. Developmental regression (which= occurred in about a third of the cases of autism) was not clustered in the months after vaccination.=20 Q3c.6 What is mumps, and what are the risks of the disease?=20 Mumps is a viral disease which is less contagious than measles or chicken p= ox. It causes swollen salivary glands. The most common complication is swelling of the testes (in about 20 percent of males= post puberty) and, less commonly, ovaries. Rarely, it can lead to sterility. Other complications are meningitis (less common t= han in measles) and acute pancreatitits. (A much longer list of complications can be found in the Merck Manual.)=20 Q3c.7 How common was mumps before routine vaccination, and how common is it= now?=20 105,00 cases were reported in 1970; by 1990 the rate of reported cases was = down to 5,300.=20 Q3c.8 How effective is the mumps vaccine?=20 The Merck Manual estimates its effectiveness at 95%. The Physician's Desk R= eference gives its effectiveness as 96%. Switzerland has gotten lower efficacy rates, for mumps, out of its strain o= f the MMR vaccine, and Swiss scientists have been comparing the efficacy of different strains to improve this situation (Swis= s Medical Weekly, http://www.smw.ch/archive/1997/127-26-360-96.html and http://www.smw.ch/arc= hive/1998/128-17-351-98.html).=20 Q3c.9 How long does the mumps vaccine last?=20 The Merck Manual describes it as "durable." "Mumps immunization provides pr= otection through the blood serum antibodies for at least 12 years, and possibly much longer." (Pantell, Fries, and Vickery)= (See also Q3c.4 for the PDR's description of the duration of all the MMR-induced antibodies.)=20 Q3c.10 What are some of the risks of the mumps vaccine?=20 "Rarely, side effects of mumps vaccination have been reported, including en= cephalitis, seizures, nerve deafness, parotits, purpura, rash, and prurittis." (Merck. Encephalitis and convulsions were al= so on Merck's list of complications for mumps itself.) According to ACIP's 1996 report on vaccine adverse reactions, "Aseptic meni= ngitis has been epidemiologically associated with receipt of the vaccine containing the Urabe strain of mumps virus, but= not with the vaccine containing the Jeryl Lynn strain, the latter of which is used in vaccine distributed in the United States." [= MMWR 45(No. RR-12), 1996]=20 Q3c.11 What is rubella, and what are the risks of the disease?=20 Rubella is a mild illness, consisting of a mild fever and rash. Rare compli= cations include ear infections and encephalitis, but the real danger is to pregnant women. During the last rubella epidemic, in 1964= , 20,000 children were born with birth defects caused by rubella. Birth defects include deafness, cataracts, microcephaly,= and mental retardation. Children born with congenital rubella are als susceptible to rubella panencephalitis in their = early teens.=20 Q3c.12 How common was rubella before routine vaccination, and how common is= it now?=20 Before the development of the rubella vaccine, epidemics used to occur at i= rregular intervals in the spring, with major epidemics at 6 to 9 year intervals. (This means that one was just about due when the = vaccine came out in 1969.) There have been no major epidemics since 1969, but the number of cases of rubella and congenit= al rubella syndrome increased starting in 1989 (Merck, also California Morbidity for November 19, 1993). (It was still a s= mall fraction of the pre-vaccine number, though, see table of disease frequencies in section 1.) "Serological surveys conduc= ted in the late 1970s and the 1980s indicated that 10 to 25 percent of United States women of child-bearing age were shown to be = susceptible to rubella." (California Morbidity, November 19, 1993) It now appears to be declining again: "Following a resur= gence of rubella and congenital rubella syndrome (CRS) during 1989-1991, the reported number of rubella cases during 1992 an= d 1993 was the lowest ever recorded." (MMWR, cited in June 9, 1994 HICNet Medical News Digest.)=20 Q3c.13 How effective is the rubella vaccine?=20 The Merck Manual estimates its effectiveness at 95%. The Physician's Desk R= eference gives its effectiveness as 99%.=20 Q3c.14 How long does the rubella vaccine last?=20 The Merck Manual describes it as "sustained." (See also Q3c.4 for the PDR's= description of the duration of all the MMR-induced antibodies.)=20 Another reference, from Heather Madrone: ************************************************************************* D. M. Horstmann "Controlling Rubella: Problems and Perspectives" _Annals of Internal Medicine_, vol. 83, no. 3, pg. 412 Horstmann found reduced antibody formation 3-5 years after administering the vaccine and 25% of those tested showed no immunity to rubella at all. ************************************************************************* Q3c.15 What are the pros and cons of vaccinating all infants for rubella ve= rsus vaccinating females only at puberty?=20 There is still some uncertainty about the most desirable rubella vaccinatio= n policy. In 1969, when the vaccine came out, it was decided to avert the expected epidemic by vaccinating all children over one= year, so that they would not spread rubella to their possible pregnant mothers - the first time one group of people was vaccinat= ed to avoid having them spread a disease to a different group of people. Supporters of this policy point out that the exp= ected epidemic didn't occur. The possible disadvantage is that we aren't sure how long the immunity lasts. Now that g= eneration of children is old enough to have children, and some of them may no longer be immune. In the past, 80% of the populatio= n was immune due to having had rubella in childhood.=20 Some countries follow a policy of vaccinating girls at puberty if they don'= t have rubella antibodies (Pantell, Fries, and Vickery). The disadvantage is that vaccine side effects are more common at this age. = The most common is joint pain, which occurs in 10% of women who are vaccinated in adolescence or later. In some cases, it = has lasted as long as 24 months. (Pantell, Fries, and Vickery) The PDR describes this same side effect in somewhat milder ter= ms, saying that it generally does not last very long and "Even in older women (35-45 years), these reactions are generally well = tolerated and rarely interfere with normal activities." It does agree with Pantell, Fries, and Vickery that the incide= nce of this side effect increases with age: 0-3% of children and 12-20% of women have joint pain, and the pain is more marked a= nd of longer duration in the adult women. A few women (between 1 in 500 and 1 in 10,000) experience peripheral neuropathy (= tingling hands). Another risk of vaccinating later is the risk that a woman may be pregnant. So far, no connection with birth = defects has been demonstrated, but women are advised to avoid pregnancy for three months after getting the vaccination.= =20 Current US policy is to vaccinate all children at 15 months, and give a boo= ster during school years. Adult women are advised to get an antibody test before becoming pregnant, and, if it comes up negat= ive, get vaccinated and wait three months before getting pregnant.=20 There has not been a rubella epidemic since 1964, either in countries which= vaccinate all children at 15 months, or in countries which vaccinate girls only at puberty.=20 Q3c.16 What are some of the risks of the rubella vaccine?=20 The PDR has a long list of possible adverse reactions (besides arthritis an= d arthralgia, usually short-lived, see above). Most of them are either mild or rare.=20 Q3c.17 When is the MMR vaccine contraindicated?=20 People with an anaphylactic or anaphylactoid allergy to eggs or neomycin sh= ould not get the vaccine. Other allergies or chicken or feather allergies are not a contraindication. Vaccination should be defe= rred in case of fever. The PDR give active untreated tuberculosis as a contraindication, but the AHFS says that there is no evid= ence of a need to worry about TB. Both give immune deficiency as a contraindication (see PDR for a long list of immune deficie= ncies involved). Immune globulin preparation or blood/blood product received in the preceding 3 months. The same contraindi= cations apply individually to measles and mumps vaccines, but the rubella vaccine can be given by itself to people with an = anaphylactic egg allergy. The other contraindications still apply to the rubella vaccine alone. (California Morbidity, October 31= , 1987)=20 Vaccine components capable of causing adverse reactions: for mumps and meas= les, chick fibroblast components; for mump, measles, and rubella, neomycin (Travel Medicine Advisor).=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D Section 3d. HiB (Hemophilus influenze B) [This section last updated September 19, 1999.]=20 Q3d.1 What is hemophilus influenze B, and what are the risks of the disease= ?=20 HiB is a bacteria which is one of the leading causes of meningitis in young= children. About 60% of cases are meningitis. The remaining 40% are cellulitis, epiglottis, pericarditis, pneumonia, sepsis, = and septic arthritis. Mortality rate can be about 5%, and there are neurologic sequelae in up to 38% of survivors.=20 Q3d.2 How common was HiB before routine vaccination, and how common is it n= ow?=20 Before routine vaccination, about 12,000 cases a year in the US, with a cum= ulative risk of 1 in 200 that a child would get the disease by age 5. A vaccine was introduced in 1985. Since the introduction = of the Hib conjugate vaccine in 1988, the race-adjusted incidence of Hib among children less than 5, has declined fro= m 41 cases per 100,000 in 1987 to two cases per 100,000 in 1993. (The incidence for people five or older remained stable. H= ib is most serious in children under 5.) (A decline of 95%, despite the fact that the National Health Interview Survey showed o= nly 67% of children 12-23 months had received at least one dose, and 36% three or more doses. This decline is attributed to = the elimination of carriage, which reduces Hib exposure even in unvaccinated children.) The CDC set a goal of eliminating = Hib in the US by 1996. (HICN708 Medical News, "[MMWR] Progress Elimination Haemophilus influenzae type b") As of Se= ptember 1999, this goal wasn't met, but there has been a significant decline; MMWR's "TABLE III. Provisional cases = of selected notifiable diseases preventable by vaccination, United States week ending September 11, 1999" records a cumula= tive total for 1998 of 788 cases, and for 1999 of 820 cases, in the US.=20 Q3d.3 How effective is the HiB vaccine?=20 Estimates from different labs vary a lot. AHFS Drug Information, after noti= ng this variability, and the uncertainty as to what antibody level is adequate for protection, says that in one study, 75% of c= hildren 18-23 months and 85% of children 24-29 months had serum anticapsular antibody levels of one microgram per millilit= er or greater. The PDR lists numerous studies, with results ranging from 100% efficacy to one study in which vaccinated childre= n had more cases of HiB than the unvaccinated group. With the exception of the latter study, all of the studies showed si= gnificant positive results, often with efficacy estimates over 90%.=20 According to a NY Times article of 12/18/90, HiB vaccine produces lower ant= ibody response among Native Americans, but the new conjugated vaccine seems to produce higher antibody response in Nat= ive American children and may protect all children at a younger age.=20 Q3d.4 How long does the HiB vaccine last?=20 The duration of immunity is unknown. However, the disease is only dangerous= to very small children.=20 Q3d.5 What are some of the risks of the HiB vaccine?=20 In a study of 401 infants, fever occurred in 2%, and redness, warmth, or sw= elling in 3.3%. All adverse reactions were infrequent and transient. (PDR) The Institute of Medicine reported in 1994 = that evidence favored rejection of a causal relationship between early onset HiB disease and conjugate vaccines, but fa= vored acceptance of a causal relationship between early onset disease in children 18 months old or more whose first vaccinati= on was with unconjugated PRP vaccine. [MMWR 45(No. RR-12), 1996]=20 Q3d.6 When is the HiB vaccine contraindicated?=20 Hypersensitivity to any component of the vaccine, including diptheria toxoi= d and thimerosal in the multi-dose presentation.=20 Vaccine components capable of causing adverse reactions: phenol, bacterial = polysaccharides, thimerosal (Travel Medicine Advisor).=20 (Note: There is currently, as of 1999, a move toward replacing thimerosal i= n vaccines, so the reference to thimerosal here may shortly be out of date.)=20 Q3d.7 What about rifampin prophylaxis?=20 An alternative to HiB vaccination is rifampin prophylaxis, but it could be = unwieldy to administer. AHFS Drug Information says that it is "effective for eradicating nasopharyngeal carriage of HiB, but t= he efficacy of the drug for prevention of secondary disease has not been firmly established."=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D Section 3e. Hepatitis B gamma globulin and hepatitis B vaccine [This section last updated on September 15, 1999.]=20 Q3e.1 What is hepatitis B, and what are the risks of the disease?=20 There are several forms of hepatitis, infections of the liver which cause j= aundice, nausea, and weakness. Hepatitis B is spread mainly by contact with infected blood and by intimate contact with bodily f= luids, such as in sexual intercourse and childbirth. However, the hepatitis B virus is far more resilient than, for example, the= AIDS virus, and the disease is not strictly a venereal disease, and can be caught even by people who are not sexually active. Hepa= titis B becomes chronic in 5-10% of those infected. Complications include hepatic necrosis, cirrhosis of the liver, c= hronic active hepatitis, and hepatocellular carcinoma. Hepatitis B is endemic throughout the world, and a serious problem in group= s at increased risk. Information about hepatitis B is available by calling 1-800-HEP-B-873. Another source of information about h= epatitis B and many other forms of liver disease is:=20 American Liver Foundation 1425 Pompton Avenue Cedar Grove, NJ 07009 A source on hepatitis B in particular is:=20 Hepatitis B Coalition 1537 Selby Ave #229 St Paul, MN 55104 (612) 647-9009 There is also a hepatitis mailing list, HEPV-L on LISTSERV@SJUVM.STJOHNS.ED= U. A Web page on Diseases of the Liver can be found at=20 http://cpmcnet.columbia.edu/dept/gi/disliv.html=20 A US government source of information on hepatitis is:=20 Hepatitis Branch Mailstop G37 CDC Atlanta, GA 30333 or call the CDC Automated Voice Information System at (404) 332-255= 3. Hepatitis B should not be confused with hepatitis A, which is more contagio= us but less serious. Hepatitis A is spread through contaminated food and water. Symptoms can be mild flulike symptoms or sever= e nausea lasting for weeks. Hepatitis A does not become chronic and is rarely fatal. Other forms of hepatitis include he= patitis C, hepatitis D, and hepatitis E, and hepatitis (being a general term for inflammation of the liver) can also be caused by = certain medications. Information on other kinds of hepatitis can be obtained from the American Liver Foundation.=20 Q3e.2 How common is hepatitis B?=20 "The estimated lifetime risk of HBV infection in the United States varies f= rom almost 100% for the highest risk groups to approximately 5% for the population as a whole." (PDR) The CDC estimates ab= out 0.75 - 1 million chronic carriers in the US, and more than 170 million are estimated worldwide.=20 Q3e.3 What is hepatitis B gamma globulin, and when is it given?=20 It is given to people who have already been exposed to hepatitis B, to boos= t their immunity. In particular, it is given to children born to mothers with hepatitis B. It should be given as soon as possible af= ter birth for the best results.=20 Q3e.4 How long does the immunity provided by hepatitis B gamma globulin las= t?=20 Two months, maybe longer.=20 Q3e.5 What are the risks and contraindications of hepatitis B gamma globuli= n?=20 No known contraindications. A couple of diseases (see PDR for more informat= ion) are listed under precautions (a weaker form of warning than contraindication - in the case of precautions gamma gl= obulin may be given, but the extra risks of giving the gamma globulin have to be weighed against the benefits). These diseases, th= ough, aren't ones a newborn is likely to have, so they would probably not apply in the case of giving it to the newborn of a = mother infected with hepatitis B.=20 Q3e.6 How effective is the hepatitis B vaccine?=20 It varies depending on the age, sex, and general health of the recipient. A= bout 96-100% in infants and children 19 and under, 94-99% in adults 20-39, 88-91% in adults 40 or older. May be lower in men t= han women. Lower (only 64% in one study) in hemodialysis patients. (AHFS Drug Information 1992) The PDR estimated 95-96= % for infants, and agrees with AHFS about the conditions which reduce effectiveness.=20 Q3e.7 How long does the hepatitis B vaccine last?=20 There is evidence that immunity lasts up to ten years, but beyond that, the= duration is uncertain, and the need for booster doses not defined. (My source for the duration is Journal Watch, 9/1/93.)=20 Q3e.8 What are some of the risks of the hepatitis B vaccine?=20 Hepatitis B has traditionally been considered one of the safest and least r= eactogenic vaccines:=20 "During clinical studies involving over 10,000 individuals distributed over= all age groups, no serious adverse reactions attributable to vaccine administration were reported." (PDR, 1993) The most= common adverse reactions were injection site soreness (22%) and fatigue (14%). A longer list of adverse reactions can be= found in the PDR. "Update: Vaccine Side Effects, Adverse Reactions, Contraindications, and Precautions," published by ACIP i= n 1996, reported that VAERS data showed a low rate of anaphylaxis (approximately one event per 600,000 doses given).= =20 More recently, controversy has been aroused by news reports, particularly i= n France, of new or reactivated cases of multiple sclerosis, and other demyelinating disorders, within two to three months fo= llowing administration of hepatitis B vaccine. Critics argue that the risk is too high for a vaccine routinely given to children n= ot directly at much risk for hepatitis B. Supporters of vaccination argue that, given the demonstrated risk of liver cancer and cir= rhosis of the liver from hepatitis B, effective vaccination programs should not be abandoned for a hypothetical risk that t= he vaccine might in rare cases lead to multiple sclerosis and other demyelinating diseases.=20 As is the case in other controversies about vaccination risks, part of the = difficulty is assessing just what effect the hepatitis B vaccine may have on demyelinating diseases. Multiple sclerosis is, in some = countries, the most common neurological disease of young adulthood. Though most commonly reported between 20 and 40, it can be= reported at younger and older ages, and, given near universal vaccination of pre-adolescents, some cases of MS are t= o be expected, simply by chance, in proximity to vaccination. Since the incidence of cases of multiple sclerosis attributed = to the vaccine, in France and elsewhere, is less than the number already expected for the age range in question, statistical analysis= is required, to determine whether the risk of MS and other demyelinating diseases is in fact higher in populations vaccinated fo= r hepatitis B, and, if so, what the risk might be.=20 Several studies have been carried out, to date, to assess this risk, and mo= re are ongoing.=20 ACIP reported, in 1996, that evidence was inadequate to establish or reject= a causal relationship between hepatitis B vaccine and demyelinating diseases of the central nervous system.=20 The French National Drug Surveillance Committee studied people who received= more than 60 million doses of hepatitis B vaccine between 1989 and 1997, and found that the prevalence of neurologica= l disease, including MS, was actually lower in this group than in the general population.=20 Three French studies, prompted by reports of MS, showed a slightly increase= d relative risk in the vaccinated population, but not one which was statistically significant. In response to this, the Frenc= h government required a risk-benefit analysis. The risk-benefit analysis did not attempt to determine whether the hepatitis B = vaccine in fact causes MS or other demyelinating diseases, but rather to use the largest possible risks which could be deriv= ed from the studies which had been done, and weigh these against the expected benefits of hepatitis B vaccine (with both being= assessed in a statistical, quantititive fashion). This study concluded that, though it isn't possible to determine yet whether the= re is an association between the hepatitis B vaccine and MS, the benefits of the vaccine for a given vaccinated pre-adolescent c= ohort would clearly outweigh the risks.=20 In Canada, the Alberta Ministry of Health reported that a preliminary exami= nation of hospital admission data between 1975 and 1995 suggests that the introduction of the hepatitis B vaccine in the m= id-1980s has not been marked by an increase in the incidence of multiple sclerosis.=20 The World Health Organization Viral Hepatitis Prevention Board (VHPB) assem= bled experts, on September 28-30, 1998, to review the epidemiology and current understanding of MS. This group examine= d data on the epidemiology of hepatitis B, the epidemiology of multiple sclerosis, from national reporting systems in the = US, Italy, and Canada, from one active pediatric surveillance system in Canada, from industry post-marketing surveillance an= d clinical data, from published studies of hepatitis B safety, and from preliminary reports of a small number of unpublished epide= miological studies in the US, France, and the UK. They tried to decide between three hypotheses for explaining the relationsh= ip between the hepatitis B vaccine and MS: 1) coincidence, 2) "triggering," in which an illness which would have occurred= anyway was unmasked by the vaccine, or 3) a true causal relationship.=20 Evidence for the hypothesis of coincidence included the lack of any statist= ically significant association with MS to date, and the fact that age and sex distributions of reported adverse events resemble age= and sex distributions seen before the vaccine. Evidence in support of an increased risk as precipitating factor was the fa= ct that some studies showed slightly increased risk of MS, though not to a statistically significant degree. Evidence against was = that another study showed no increased risk. The group concluded that the evidence for an association between the hepatitis = B vaccine and MS was weak, and did not meet the criterion for causality.=20 Response to this data has shown a rare divergence in public health policies= . The French National Network of Public Health, while still recommending the vaccine as useful to pre-adolescents, conclude= d that, because of differences in individual risk for hepatitis B and for side effects of the vaccine and "the need for a medical= consultation including the personal and family history," the vaccination program for pre-teens in the schools would be suspended. Th= is suspension was announced on October 1, 1998. Public health departments in several other countries, along with the = World Health Organization, criticized the French government for making a decision based more on politics than on the actual = risks, and reaffirmed existing vaccination policies. The US Congress held hearings on the subject, while the CDC affirmed that "= The scientific evidence to date does not support hepatitis B vaccination causing MS or other demyelinating diseases." (http:= //www.cdc.gov/nip/vacsafe/fs/qhepb.htm#7) Several organizations concerned with hepatitis B and multiple sclerosis, in the US = and Canada, came out with statements supporting continued hepatitis B vaccination.=20 As I write this section of the FAQ, the CDC reports that at least six resea= rch projects are underway, in the US, France, and the UK, to examine what relationship, if any, exists between the hepatitis = B vaccine and multiple sclerosis. In the meantime, most countries are continuing to recommend universal hepatitis B vaccinatio= n for infants and for pre-teens who have not already been vaccinated.=20 Q3e.9 When is the hepatitis B vaccine contraindicated?=20 Sensitivity to yeast or any other component of the vaccine. Pregnancy is no= t a contraindication to hepatitis B vaccination. A previous anaphylactic response to the vaccine is a contraindication to furt= her doses.=20 Vaccine components capable of causing adverse reactions: aluminum phosphate= , thimerosal, and formaldehyde (Travel Medicine Advisor). (Note, though, that as of September 1999, a thimerosal f= ree hepatitis B vaccine is available.)=20 Q3e.10 Why did the ACIP and AAP change their recommendation about the hepat= itis B vaccine?=20 Up until 1992, the recommendation was that hepatitis B vaccine be given onl= y to people in high risk groups for hepatitis B: people whose professions exposed them to blood, people at extra risk due to= their sexual practices or intravenous drug use, and certain populations (such as Southeast Asian immigrants) with a high in= cidence of the disease. The chief reason was cost; it was felt to be not cost-effective to vaccinate low-risk groups.=20 Unfortunately, this policy was not successful in checking the spread of hep= atitis B. It proved difficult to identify high-risk people, and high-risk people did not volunteer in large numbers to be vacci= nated. For this reason, in 1992, the ACIP recommendation was switched to vaccination of teens and adults in high-risk= groups and universal vaccination of infants. The AAP made a similar recommendation but would also like to extend hepatitis B= vaccination to all adolescents, if possible.=20 The American Liver Foundation also supports hepatitis B vaccination of infa= nts, and their pamphlet on the subject suggests a variety of ways in which even young children could come in contact with the= virus (through contact with blood, etc.). Though young children are at low risk of catching hepatitis B, their risk of devel= oping the chronic form of the disease if they do catch it is higher than for adults.=20 The new policy was well-received internationally, and 30 countries now have= universal infant HBV vaccination programs. Many physicians remain skeptical, however, and a survey in North Carolina s= howed one third of pediatricians and <20% of family physicians supporting the new guidelines (Journal Watch, 9-1-93). (U= pdate: Journal Watch for Jan 15, 1995/Feb 7, 1995 reports that this vaccine is gaining physician acceptance, citing Arch= Pediatr Adolesc Med Sep 1994, p. 936)=20 Why the resistance? One reason is a reluctance to give low-risk infants yet= another vaccination. Another is doubt about the duration of HBV vaccine. There is evidence that it lasts up to 10 years, bu= t we do not know yet whether it wears off beyond that point. There is concern that infants vaccinated for HBV may lose immun= ity during adolescence, when the risk of catching the disease is greatest. An alternative would be to vaccinate all children = at age 10 and give a booster at age 20. But compliance would likely be lower at age 10 than in infancy. Hepatitis B vaccine is adm= inistered in three shots over the course of six months, and it would be difficult to get preteens to all come in for the full serie= s. Also, 8% of hepatitis B infections occur before age 10, and the deadly form is three times greater in children (NY Times, 3/3/93:B8= ). Boosters could be given later to infants vaccinated for HBV if immunity proves to lapse.=20 Hepatitis B vaccine is also often recommended for travel purposes.=20 Q3e.11 Does vaccination for hepatitis B affect one's ability to donate bloo= d?=20 ************************************************************************* From=20Gregory Froehlich, MD (from a posting to sci.med): First, hepatitis B *antigen* is used to make Hep B vaccine. The antigen is grown in yeast culture; formerly, it was purified from the blood of people who were chronic hepatitis carriers. Antibodies are used in the gamma globulin shots used for hepatitis A or for passive immunization against hepatitis B if you're exposed. The local blood bank does not specifically test for exposure to hepatitis A (the kind you'd get from contaminated water). If a person has an active hep A infection, it will be picked up by elevated liver enzymes; if the person had such an infection in the past, it's over and done with--hep A doesn't give you a chronic, subclinical infection. Antibodies to hepatitis A should not preclude blood donation. They check for chronic hep B carriers by testing for hep B surface antigen. They test for recent hep B infection by testing for hep B core antibody. This antibody does not carry disease, but rather indicates that the person was recently infected and might or might not still be infectious. They do not test for surface *antibody*, which would indicate either (a) former hep B infection which was cleared, or (b) immunization against hep B--in either case, not infectious. I've got hep B surface antibody, because I was immunized; I can still donate blood. Blood banks also test for hepatitis C antibody; people with this antibody can still be infectious. ************************************************************************* Q3e.12 Do people who have showed up positive on the blood banks' tests for = hepatitis B exposure still need to be vaccinated?=20 It is still useful to be vaccinated, because some of the people who show up= positive on the blood bank tests are false positive.=20 Q3e.13 I will be travelling to an area where hepatitis B shots are recommen= ded, but I have less than six months before I leave. Is there an accelerated schedule for hepatitis B vaccination?=20 _Travel Medicine Advisor_ lists an accelerated schedule, with 3 doses at 0,= 30, and 60 days. With this schedule, a fourth dose is recommended at 12 months if there is still a risk for hepatitis B exposu= re.=20