ATLANTA The Advisory Committee on Immunization Practices (ACIP) recently updated its recommendations pertaining to the precautions, contraindications, side effects and adverse reactions associated with vaccines to ensure consistency with the Institute of Medicine's (IOM) conclusions.
The updated information concerns potential adverse events associated with vaccination for hepatitis B, DTP, poliomyelitis, measles and mumps.
Based on reports to the Vaccine Adverse Events Reporting System (VAERS), the estimated incidence rate of anaphylaxis among hepatitis B virus (HBV) vaccine recipients is low (approximately one event per 600,000 doses distributed). Two of these adverse events occurred in children.
Only one case of anaphylaxis occurred among 100,763 children from 10 to 11 years who had been vaccinated with recombinant vaccine in British Columbia, and no adverse events were reported among 166,757 children who had been vaccinated with plasma-derived vaccine in New Zealand.
Although none of those who developed anaphylaxis died, this adverse event can be fatal. In addition, HBV vaccine can in rare instances cause a life-threatening hypersensitivity reaction in some people. Therefore, subsequent vaccination with HBV vaccine is contraindicated for people who have previously had an anaphylactic response to a dose of this vaccine, the ACIP said.
Whether pertussis vaccine causes or is only coincidentally related to serious acute neurologic illnesses, or reveals an inevitable event, has been difficult to determine conclusively.
Nonetheless, the updated recommendation concluded that the National Childhood Encephalopathy Study (NCES) and other controlled epidemiologic studies have provided evidence that diphtheria-tetanus-pertussis vaccine (DTP) can cause acute encephalopathy. This adverse event is rare, with an estimated risk of zero to 10.5 episodes per million DTP vaccinations.
After reviewing the follow-up data, the IOM concluded that the NCES provided evidence of an association between DTP and chronic nervous system dysfunction in children who experienced a serious acute neurologic illness after vaccination with DTP. The IOM considered three possible explanations but concluded that the NCES data do not support one explanation over another.
The IOM and a subcommittee of the National Vaccine Advisory Committee (NVAC) concluded that the results were insufficient to determine whether DTP administration before the acute neurologic event influenced the potential for neurologic dysfunction 10 years later. The ACIP concurs with this evaluation.
The IOM also concluded the evidence did not prove a causal relationship between DTP and sudden infant death syndrome (SIDS).
Although very rare, severe hypersensitivity reactions to tetanus toxoid may occur after receipt of vaccines containing tetanus toxoids; these reactions can be life-threatening, the report stated.
Based on its findings, the IOM concluded that vaccines containing tetanus toxoids can trigger the onset of Guillain-Barré syndrome in adults. Those who have a history of Guillain-Barré syndrome associated with a particular vaccine may be at increased risk for recurrent Guillain-Barré syndrome after subsequent doses of that vaccine. No increased risk for the syndrome has been observed with the use of DTP in children, according to the ACIP report issued by the Centers for Disease Control and Prevention (CDC).
Tetanus vaccination rarely has been associated with the recurrence of Guillain-Barré syndrome. Therefore, the decision to administer additional doses of tetanus toxoid to persons who have had GBS within six weeks after receiving tetanus toxoid should be based on the benefits of subsequent vaccination and the risk for recurrence of Guillain-Barré syndrome.
Vaccines containing tetanus toxoids have been associated with brachial neuritis in adult vaccinees, with a relative risk of five to 10 in comparison with the population-based background incidence and a one-month attributable incidence of approximately one-half to one case per 100,000 recipients of tetanus toxoid.
The ACIP made the following updated recommendations for polio myelitis prevention and immunodeficiency and adverse reactions:
If a household contact of an immunodeficient person is vaccinated inadvertently with oral poliovirus vaccine (OPV), the OPV recipient should avoid close physical contact with the immunocompromised person for approximately four to six weeks after vaccination.
The ACIP now says if such contact cannot be avoided, infection-control practices should be implemented. These include rigorous hygiene and hand washing after contact with feces and avoiding contact with saliva. These practices are an acceptable, but probably less effective, alternative than refraining from contact.
In rare instances, administration of OPV has been associated with paralytic poliomyelitis in healthy recipients and their contacts; and very rarely has caused fatal paralytic poliomyelitis in immunocompromised people.
Initial reports of two studies conducted in Finland suggested that OPV might cause Guillain-Barré syndrome. These studies identified an apparent increased incidence of Guillain-Barré syndrome that was temporally associated with mass OPV vaccination of children and adults who had previously received inactivated poliovirus vaccine (IPV). However, available data do not indicate a measurable increased risk for Guillain-Barré syndrome after receipt of OPV.
A re-analysis of the data derived from the Finland study and an analysis of an observational study conducted in the United States have not demonstrated a causal relationship between OPV and GBS in infants.
Because OPV contains trace amounts of streptomycin, bacitracin and neomycin, its use is contraindicated in people who have previously had an anaphylactic reaction to OPV or to these antibiotics.
The ACIP also revised its statement concerning personal or family history of convulsions associated with MMR vaccine. Studies conducted to date have not established an association between vaccination with measles-mumps-rubella (MMR) and the development of a residual seizure disorder in children with such histories.
The committee also concluded that measles vaccine significantly reduces the likelihood of developing subacute sclerosing panencephalitis (SSPE). The administration of live measles vaccine does not increase the risk for SSPE, regardless of whether the vaccine recipient has had measles infection or has previously received live measles vaccine.
Surveillance of adverse reactions indicates that MMR vaccine can, in rare circumstances, cause clinically apparent thrombocytopenia within two months after vaccination. However, the risk of thrombocytopenia during rubella or measles infection is much greater than the risk after vaccination.
Children who have a history of thrombocytopenic purpura or thrombocytopenia may be at increased risk for developing clinically significant thrombocytopenia after MMR vaccination. The decision to vaccinate should depend on the benefits of immunity to measles, mumps and rubella and the risks for recurrence or exacerbation of thrombocytopenia after vaccination or during natural infections with measles or rubella. Serologic evidence of measles immunity may be sought in lieu of MMR vaccination.
Allergic reactions rarely occur after the administration of MMR. Immediate, anaphylactic reactions to MMR are extremely rare. In the past, people with a history of anaphylactic reactions following egg ingestion were considered to be at increased risk for serious reactions after receipt of measles-containing vaccines, which are produced in chicken embryo fibroblasts. Therefore, the ACIP is re-evaluating whether skin testing and the use of special protocols are routinely necessary when administering MMR or other measles-containing vaccines to those who have a history of anaphylactic-like reactions after egg ingestion.
Measles-containing vaccines contain hydrolyzed gelatin as a stabilizer, but only one anaphylactic reaction has been reported in a person with anaphylactic sensitivity to gelatin after receiving the MMR vaccine licensed in the United States. Therefore, the ACIP is currently considering recommendations for vaccination of those who have had an anaphylactic reaction to gelatin or gelatin-containing products. Until then, the ACIP recommends using extreme caution when vaccinating such people with measles-containing vaccine.
Recent evidence concerning the administration of immune globulins suggests that high doses of immune globulins can inhibit the immune response to measles vaccine for more than three months. If administration of any immune globulin preparation becomes necessary because of imminent exposure to disease, MMR or its component vaccines can be administered simultaneously with the immune globulin inoculation, the report stated. Vaccination, however, should be repeated after a predetermined interval.
The ACIP also revised statements pertaining to immunocompromised people. Replication of vaccine viruses can be enhanced in those with immune deficiency or immuosuppression, as occurs with leukemia, lymphoma, generalized malignancy or therapy with alkylating agents, antimetabolites, radiation or corticosteroids. Evidence based on case reports has linked measles vaccine and measles infection to subsequent death in some severely immunocompromised children.
Patients who have such conditions or are undergoing such therapies (excluding most HIV-infected patients) should not be given live measles virus vaccine. Patients with leukemia in remission who have not received chemotherapy for at least three months may receive live-virus vaccines.
The ACIP recommended that MMR vaccine be administered to all asymptomatic people with HIV because of the increased risk for severe complications associated with measles infection and the absence of serious adverse events after measles vaccination among those with HIV. Until the ACIP officially makes a recommendation, it may be prudent to withhold MMR or other measles-containing vaccines from HIV-infected people with evidence of severe immunosuppression. The report also provides recommendations on the use of immune globulin (IG) in patients infected with HIV.
Children with asymptomatic HIV infections should receive MMR as soon as possible upon reaching their first birthday, and MMR vaccine should be considered for all symptomatic HIV-infected children who have no evidence of severe immunosuppression.
Aseptic meningitis has been epidemiologically associated with receipt of the mumps vaccine containing the Urabe strain of mumps virus, but not with the vaccine containing the Jeryl Lynn strain, which is used in vaccine distributed in the United States, the report stated.
Although sensorineural deafness following mumps vaccination has been reported rarely, the data are inadequate to distinguish vaccine-associated causes from causes that are unrelated to the vaccine.
Mumps-containing vaccines are produced in chick embryo fibroblasts. The concerns and recommendations regarding allergic reactions are the same as for MMR vaccine.
Monovalent mumps or rubella-mumps vaccine should be given at least two weeks before the administration of an immune globulin preparation or deferred until approximately three months after the administration of an immune globulin preparation.
Patients with leukemia in remission whose chemotherapy has been terminated for at lease three months may receive live mumps virus vaccine. Short term or low to moderate dose steroid therapy usually does not contraindicate administration of live virus vaccine; however, mumps vaccine should be avoided if systemic immunosuppressive levels are reached by prolonged, extensive topical application. Patients with suppressed immune responses should not be given live mumps virus vaccine.
For more information:
- CDC. Update: Vaccine side effects, adverse reactions, contraindications and precautions; recommendations of the advisory committee on immunization practices. MMWR. 1996;45:1-35.
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