Immunization of egg-allergic individuals with egg- or chicken-derived vaccines

Viruses used in several vaccines are propagated in embryonated eggs. These vaccines contain variable quantities of residual egg or chicken proteins and pose risks when administered to egg- or chicken-sensitive persons. This article highlights differences in how vaccines are prepared, with emphasis on the quantitation of residual egg-derived protein in each vaccine. Published reports on the frequency and severity of these vaccine-induced allergic reactions are reviewed, and an algorithm is provided for the preimmunization evaluation of egg-sensitive persons.