Purpose of review: Vaccines have had a major effect on controlling the spread of infectious diseases, but use of certain vaccines was linked to potential allergic and autoimmune side effects in healthy and often in certain high-risk populations. In this review the authors summarize the current knowledge of such risks.
Recent findings: Immediate systemic allergic reactions after vaccination with commonly used vaccines are extremely rare. Use of certain vaccines was linked to potential allergic side effects in healthy and often in certain high-risk populations. The authors review the data on the risk associated with important vaccines including influenza, smallpox, pneumococcus, Japanese encephalitis, Bacille Calmette-Guerin, pertussis, and measles, mumps, and rubella. Two main components were identified as a source for allergic reactions in vaccines: gelatin and egg protein. There is growing interest in the potential interactions between infant vaccination and risk for development of atopic disease. In addition, there is concern that genetic risk for atopy influences capacity to respond to vaccination during infancy. There is no evidence that vaccines such as Bacille Calmette-Guerin; pertussis; influenza; measles, mumps, and rubella; or smallpox have an effect on the risk of the development of atopy later in life. Immunotherapy provides an efficacious and safe method for the treatment of allergic conditions by immunomodulation of the immune system. The possibility of vaccination triggering or unmasking autoimmunity in genetically susceptible individuals cannot be ruled out, but for the general population the risk-to-benefit ratio is overwhelmingly in favor of vaccinations.
Summary: Childhood vaccination remains an essential part of child health programs and should not be withheld, even from children predisposed to allergy. Vaccinations are safe, but special attention should be taken in high-risk individuals with anaphylactic reactions to foods, and in patients with autoimmune diseases.