Chapter 116. Immunization Principles and Vaccine Use (Part 10)

An illuminating example is the case of Rotashield, a rhesus reassortant rotavirus vaccine, which was introduced for routine use in the United States in the late 1990s. Within 9 months of its introduction, cases of intussusception were reported by the CDC to be temporally associated with the administration of the initial vaccine dose. This report led first to the cessation of the vaccines use and subsequently to its withdrawal from the market and the discontinuation of its production. The withdrawal of the vaccine in the United States made its use impossible in developing countries, where the risk of any...
Nội dung trích xuất từ tài liệu:
Chapter 116. Immunization Principles and Vaccine Use (Part 10) Chapter 116. Immunization Principles and Vaccine Use (Part 10) An illuminating example is the case of Rotashield, a rhesus reassortantrotavirus vaccine, which was introduced for routine use in the United States in thelate 1990s. Within 9 months of its introduction, cases of intussusception werereported by the CDC to be temporally associated with the administration of theinitial vaccine dose. This report led first to the cessation of the vaccines use andsubsequently to its withdrawal from the market and the discontinuation of itsproduction. The withdrawal of the vaccine in the United States made its useimpossible in developing countries, where the risk of any increase inintussusception would have been dramatically outweighed by the benefit ofdecreased rotavirus mortality rates. It is now apparent that the susceptibility tointussception is age related, with virtually no events in children States and recommended for routine use beginning at ≤2 months of age. In theinterim, some 4–5 million infants have died of rotavirus diarrhea in the developingworld; most of these deaths could have been prevented by the original rhesusrotavirus vaccine. Vaccine components, including protective antigens, animal proteinsintroduced during vaccine production, and antibiotics or other preservatives orstabilizers, can certainly cause allergic reactions in some recipients. Thesereactions may be local or systemic, including urticaria and serious anaphylaxis.The most common extraneous allergen is egg protein derived from the growth ofmeasles, mumps, influenza, and yellow fever viruses in embryonated eggs.Gelatin, used as a heat stabilizer, has been implicated in rare but severe allergicreactions. Local or systemic reactions (probably due to antigen-antibodycomplexes) can result from the too frequent administration of vaccines such as Tdor rabies vaccine. Because live-virus vaccines can interfere with tuberculin testresponses, necessary tuberculin testing should be done either on the day ofimmunization or at least 6 weeks later. Use of Vaccines in Special Circumstances Breast Feeding Neither killed nor live vaccines affect the safety of breast feeding for eithermother or infant. Breast-fed infants can be immunized on a normal schedule. Evenpremature infants can be immunized at their appropriate chronologic age.Seroconversion in response to hepatitis vaccine at birth may be impaired in somepremature infants with birth weights of Limited studies in HIV-infected individuals have found no increase in therisk of adverse events from the use of live or inactivated vaccines. It is notsurprising that immune responses may not be as vigorous in immunocompromisedindividuals as in those with a normal immune system; therefore, persons known tobe infected with HIV should be immunized with recommended vaccines in thesame manner as individuals with a normal immune system and as early in thecourse of their disease as possible, before immune function becomes significantlyimpaired. If MMR immunization is indicated, HIV-infected patients may receivethe standard attenuated vaccine; if polio vaccination is required, these patients andtheir household contacts should receive inactivated polio vaccine. Albeit prudent, it is not necessary to test for HIV before making decisionsabout the immunization of asymptomatic individuals from known HIV riskgroups. Live attenuated vaccines are contraindicated in otherimmunocompromised patients, including those with congenital immunodeficiencysyndromes, those who have undergone splenectomy, and those who are receivingimmunosuppressive therapy. Passive immunization with immunoglobulinpreparations or antitoxins can be considered in individual cases, either aspostexposure prophylaxis or as part of the treatment of established infection. Travel (See also Chap. 117) The International Sanitary Regulations allowcountries to impose requirements for yellow fever and killed cholera vaccines as acondition for admission, even though the latter vaccine is not an effective publichealth tool. Travelers should know whether these vaccines are required for entryinto the countries on their itinerary to avoid being turned back or immunized onthe spot, with the inherent danger of unsafe injections in poor developingcountries. Infants, children, and adults should have all routine immunizationsupdated before traveling, especially to developing countries, with particularattention to polio, measles, and DTaP or Tdap, depending on age. Immunity tohepatitis A and hepatitis B is advisable for travelers. Special-use vaccines (Table116-2), including rabies, typhoid ...