ALLERGY TO VIRAL AND RICKETTSIAL VACCINES: II. Allergic Reactions Encountered and Further Studies with Refined Influenza and Mumps Vaccines in Allergic Children

BECAUSE of the avidity that rickettsiae and viruses have for embryonal tissues, the chick embryo was found to be a desirable culture medium for the preparation of immunizing vaccines. The vaccines which are considered of value as immunizing agents are yellow fever, typhus, Rocky Mountain spotted fever or tick typhus, equine encephalomyelitis, influenza A and B strains of virus, and mumps. However, allergic reactions have resulted as a side-effect from the use of such vaccines in egg-sensitive persons. Injection of egg protein, as a diagnostic procedure, in exquisitely sensitive children has resulted in profound anaphylactic-shock reactions 1 and death. 2 How frequently one may expect to encounter such persons was estimated by us in previous reports. 3 We found that 20% of 500 allergic children 3c demonstrated a dermal sensitivity to egg proteins. In only 5% was this sensitivity of clinical significance. We propose in this study to analyze and