Key Points
ÎÎImmunization is perhaps the greatest public health achievement of all
time, having significantly reduced the morbidity and mortality of many
infectious diseases.
ÎÎThere are approximately 235 million doses of vaccines administered in
the United States each year.
ÎÎAnaphylactic reactions to vaccines are estimated to occur at a rate of
approximately 1 per million doses.
ÎÎPatients with suspected allergy to vaccines or vaccine components
should be evaluated by an allergist/immunologist.
ÎÎMost patients with suspected allergy to vaccines can receive vaccination
safely.
Diagnosis and Assessment
ÎÎMild local reactions and constitutional symptoms, such as fever, after
vaccinations are common and do not contraindicate future doses. Rarely,
delayed-type hypersensitivity to a vaccine constituent may cause an
injection site nodule, but this is not a contraindication to subsequent
vaccination. (C)
ÎÎAll serious events occurring after vaccine administration should be reported
to the Vaccine Adverse Event Reporting System (http://vaers.hhs.gov/),
even if it is not certain that the vaccine was causal. (C)
ÎÎMeasuring levels of IgG antibody to the immunizing agent in a vaccine
suspected of causing a serious adverse reaction to determine if they are at
protective levels can help determine whether or not subsequent doses are
required. (B)
ÎÎAll suspected anaphylactic reactions to vaccines should ideally be evaluated
in an attempt to determine the culprit allergen. (B)
ÎÎIgE-mediated reactions to vaccines are more often caused by vaccine
components, such as gelatin or egg protein, than the immunizing agent
itself. (B)
ÎÎPatients who have had an apparent anaphylactic reaction after immunization
should undergo immediate-type allergy skin testing to help confirm that the
reaction was IgE-mediated and to determine the responsible component of
the vaccine. (B)
