What is a vaccine allergy?
A vaccine allergy is an allergic reaction that occurs after receiving a vaccine. This can happen with any type of vaccine and is rare. Mild local reactions and fever after vaccination are common and do not indicate vaccine allergy.
What causes vaccine allergic reactions?
After you receive a vaccine, the ingredients of the vaccine activate certain parts of the immune system. This typically helps you form good antibodies to give protection against the illness being vaccinated against. If your immune system doesn’t tolerate any part of the vaccine and instead gets stimulated along the allergy pathway, this can cause anaphylaxis (severe allergic reaction).
What are the symptoms of a vaccine allergy?
An allergic reaction to a vaccine typically occurs within minutes of receiving the injection but can present up to 2 hours later. Symptoms include:
- Hives
- Swelling
- Breathing problems
- Low blood pressure
- Nausea, vomiting, or diarrhea
- Dizziness
Some purported long-term effects of vaccinations, such as autism or ADHD, are not supported by medical studies. Also, guidelines now state it is not necessary to ask about egg allergy prior to administering influenza vaccines as even patient with confirmed egg allergy can safely receive the influenza vaccine yearly.
How are vaccine allergies treated?
It is important to get evaluated by a board-certified allergist if you feel you have experienced a vaccine allergy as testing may be indicated. Depending on the evaluation, your allergist can give guidance on further vaccinations.