Pediatric Vaccine Safety Monitoring
Injection site reactions and delayed urticaria or rash often occur after vaccine administration and may be mistaken for a hypersensitivity reaction. True allergic reactions appear to be rare. The incidence of anaphylaxis after vaccine administration is estimated to be between 0.65 and 1 reaction per million vaccine doses.
Caubet and Ponvert classify systemic reactions to vaccines into three categories: 1) delayed urticaria with or without angioedema and rash, likely resulting from a nonspecific activation of the immune system and degranulation of mastocytes, 2) immediate reactions presenting with urticaria, angioedema, rhinitis, wheezing, and hypotension, or 3) undefined reactions, such as Guillain-Barre syndrome with certain strains of the influenza vaccine. Patients with an immediate or delayed hypersensitivity reaction should be evaluated by an allergist. Skin testing is recommended in patients with an immediate allergic reaction after vaccine administration, or in those allergic to gelatin, latex, yeast, or eggs. Measurement of serum IgE levels may also be beneficial in some cases. If skin testing is negative, immunization can proceed. If positive, antibody titers should be checked to determine if additional doses are needed. If additional doses are required, graded doses may be administered according to recommendations published by the American Academy of Pediatrics.
For patients with egg allergy, skin tests for influenza vaccine have been shown to provide false positive results and are not considered useful in predicting response. According to current guidelines from the Advisory Committee for Immunization Practices (ACIP), individuals who developed hives without cardiovascular, respiratory, or gastrointestinal symptoms with an earlier exposure to the vaccine may receive the inactivated influenza vaccine if observed for at least 30 minutes after vaccination.
Hypersensitivity Reactions to Vaccines
Injection site reactions and delayed urticaria or rash often occur after vaccine administration and may be mistaken for a hypersensitivity reaction. True allergic reactions appear to be rare. The incidence of anaphylaxis after vaccine administration is estimated to be between 0.65 and 1 reaction per million vaccine doses.
Caubet and Ponvert classify systemic reactions to vaccines into three categories: 1) delayed urticaria with or without angioedema and rash, likely resulting from a nonspecific activation of the immune system and degranulation of mastocytes, 2) immediate reactions presenting with urticaria, angioedema, rhinitis, wheezing, and hypotension, or 3) undefined reactions, such as Guillain-Barre syndrome with certain strains of the influenza vaccine. Patients with an immediate or delayed hypersensitivity reaction should be evaluated by an allergist. Skin testing is recommended in patients with an immediate allergic reaction after vaccine administration, or in those allergic to gelatin, latex, yeast, or eggs. Measurement of serum IgE levels may also be beneficial in some cases. If skin testing is negative, immunization can proceed. If positive, antibody titers should be checked to determine if additional doses are needed. If additional doses are required, graded doses may be administered according to recommendations published by the American Academy of Pediatrics.
For patients with egg allergy, skin tests for influenza vaccine have been shown to provide false positive results and are not considered useful in predicting response. According to current guidelines from the Advisory Committee for Immunization Practices (ACIP), individuals who developed hives without cardiovascular, respiratory, or gastrointestinal symptoms with an earlier exposure to the vaccine may receive the inactivated influenza vaccine if observed for at least 30 minutes after vaccination.