You’re probably not allergic to vaccines

There is little chance you are actually allergic to vaccines and, if you are, your allergist can vaccinate you. According to a recent article by two McMaster physicians in the Canadian Medical Association Journal, only one in 760,000 vaccinations will respond with anaphylaxis.

April 8, 2019

Derek Chu (left) is a fellow in clinical immunology and allergy in the Department of Medicine and Zainab Abdurrahman is an assistant clinical professor in the Department of Pediatrics.

Experts Featured In This Story

Zainab Abdurrahman
Zainab Abdurrahman

Assistant Clinical Professor (Adjunct)

See Profile
Derek Chu
Derek Chu

Assistant Professor

See Profile

There is little chance you are actually allergic to vaccines and, if you are, your allergist can vaccinate you.

Only one in 760,000 vaccinations will respond with anaphylaxis. For all other side effects, there are ways to address any problems that arise.

Five facts about allergies to vaccines, pulled together by two McMaster University physicians, were published today in the Canadian Medical Association Journal. Derek Chu is a fellow in clinical immunology and allergy in the Department of Medicine and Zainab Abdurrahman is an assistant clinical professor in the Department of Pediatrics. The pair were also interviewed as part of a CMAJ podcast.

Five things to know about vaccine allergies

  • 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.

  • 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.

  • 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 an 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.

  • It may be a reaction to the rubber stopper.

If you have a latex allergy, it will be the rubber stopper or preloaded syringe, not the vaccine that causes a problem.

  • Your allergist can safely vaccinate you.

If you really do have a vaccine allergy, allergists can help immunize you through techniques such as graded administration, or giving the vaccine a little at a time.

Three scientists standing together in a laboratory. Two are holding small bottles.

New drug candidate reverses metabolic liver disease and fibrosis, pre-clinical data shows

The findings point to a potential new treatment for millions of people, addressing a critical gap where no approved drugs exist in Canada.
A smiling person in the background, with their hand holding a vial of medicine in the foreground.

‘Helper molecule’ discovery offers new hope against drug-resistant fungal infections

Postdoc’s painstaking sleuthing yields the Wright Lab’s third groundbreaking antimicrobial discovery in a year.
Two smiling people working at a computer in a lab. One is wearing a lab coat.

How McMaster is advancing healthy aging through research, partnerships and impact

‘Aging doesn’t happen in silos.’ At the McMaster Institute for Research on Aging, researchers from all faculties work together to study the complex, interconnected factors affecting how we age.