Immunizations have dramatically reduced the burden of many infectious diseases worldwide. The seasonal influenza vaccine has a strong track record of successfully reducing influenza infection. The 2009 H1N1 vaccine is expected to protect many individuals from H1N1 infections and its associated respiratory complications, including hospitalizations and death from pneumonia.

However, persons with a history of severe egg allergy or a history of a previous allergy to an influenza vaccine are at risk for an allergic reaction to the seasonal influenza vaccine and the H1N1 vaccine, because both vaccines contain very small amounts of egg protein.

Fortunately, the publication of Adverse Reactions to Vaccines provides a clear, evidence-based approach to the evaluation of the person at risk for allergic reactions to vaccines, including the influenza vaccines.

The evidence shows that most people with a history of egg allergy or a history of previous reaction to an influenza vaccine can in fact be immunized safely after allergy testing. This evaluation should be performed by an allergist. In some cases graded dosing of the vaccine is recommended.

Adverse Reactions to Vaccines covers the evaluation and management of suspected allergy to all vaccines including diphtheria, tetanus, measles, mumps, rubella, varicella, zoster, typhoid, and yellow fever. Evaluation strategies include skin testing to vaccines and components, serum specific IgE antibody testing, and serologic testing for protective antibody responses to vaccines. The paper provides guidelines on when vaccines should not be given because of possible adverse effects.

The 2 key points of Adverse Reactions to Vaccines are (page S2):

1. patients with suspected allergy to vaccines or vaccine components should be evaluated by an allergist/immunologist and
2. most patients with suspected allergy to vaccines can receive vaccination safely