Only one in 760,000 vaccinations will respond with anaphylaxis and for all other side effects, there are ways around any problem, a new study shows.

Five facts about allergies to vaccines, pulled together by two McMaster University physicians, were published in the Canadian Medical Association Journal (CMAJ), are:

1. Immunoglobulin E (IgE)-mediated allergies to vaccines are extremely uncommon: Responding to a vaccine with hives, swelling, wheezing or anaphylaxis happens in about one of 760,000 vaccinations. It will start within minutes of the vaccination, is unlikely to begin after 60 minutes and highly unlikely to occur after four hours.
2. Signs like fever, local pain or local swelling are not signs of allergy: These responses to a vaccine may happen as much as seven to 21 days after a vaccination, but they are not an allergic reaction.
3. With the exception of the yellow fever vaccine, an egg allergy is no reason to avoid vaccinations:No special precaution is needed when people who have an egg allergy have influenza, MMR (mumps, measles and rubella vaccines given together), or rabies vaccination because the amount of egg protein it may contain is too minuscule, says the Public Health Agency of Canada and the Canadian Pediatric Society.
4. It may be a reaction to the rubber stopper: This happens for latex allergies- it will be the rubber stopper or preloaded syringe, not the vaccine that causes a problem.

If a patient does have a vaccine allergy, allergists can help immunize them through techniques such as graded administration or giving the vaccine a little at a time.