Allergy to Vaccines
Vaccines are rarely known to cause allergic reactions. Most vaccines cause rashes, swelling which is a side-effect of the infection. As with any medication, vaccines can have lot of side effects such as fever, local redness or swelling. This is not an allergy.
An allergy occurs when the body reacts to a specific substance or allergen. An allergic reaction can be a rash, shortness of breath, wheezing or swelling of the face. These symptoms occur almost immediately, or within an hour or so after the injection.
What type of allergy occurs due to vaccines?
Although a person can be allergic to any vaccine or any of its components, but it is quite rare. However, some people are mostly allergic to the diphtheria-tetanus vaccine that is administered during the initial period of life. People who are allergic to the diphtheria-tetanus vaccine will have allergy to some other vaccines also; because many other newer vaccines such as the meningitis vaccine has been developed using this vaccine as base.
People who are allergic to egg are also prone to vaccine allergy-
Some vaccinations, including the MMR and influenza vaccines are made using chicken, egg or related substances. Therefore if one is allergic to eggs, then one may be allergic to egg-based vaccines.
But, if an allergy test is conducted, and based on the allergy test, it is found out that an egg-allergic child is not allergic to the MMR vaccine, he receives the MMR vaccine without any problem. However, this does not apply to other egg-based vaccines like the influenza vaccine. In this case, if a child is allergic to eggs, he must not receive the vaccine unless specific "flu- vaccine allergy tests" are performed by an allergist. There are some people who despite having an egg allergy are not allergic to the flu vaccine.
Is there an alternative flu prevention for high-risk people with egg allergy who are unable to take the flu vaccine?
A high-risk person with suspected egg allergy can use other flu medications within 24 hours of developing flu symptoms. The medication prevents the progression of the flu.
Vaccine ingredients that may cause allergic reactions -
Allergic reactions to vaccine and its components are not quite common. The most common difficulties are encountered with hypersensitivity to chickens, eggs, mercury, certain antibiotics, or to gelatin which are there present in the vaccines.
If a child is allergic to antibiotics:
- Polio vaccine includes antibiotics such as streptomycin, neomycin, and polymyxin B. The MMR and the varicella vaccine also have nominal amounts of the antibiotic neomycin. Most of the allergic reactions to these antibiotics are usually mild skin rashes and itching. However, if the child develops a severe allergy with symptoms such as wheezing, breathing trouble, dizziness and more, it is better to avoid these vaccines altogether.
- It is important to note that none of the vaccines which are administered contain penicillin or penicillin-related antibiotics. So, it is safe to vaccinate anyone, even though he/she may be allergic to penicillin.
If the child has chicken and egg allergies:
- The measles-mumps-rubella vaccine (MMR) does contain a small amount of egg protein. And if a child is allergic to egg, you must go in for an allergy test. In most cases, those with egg allergies are quite unlikely to have an anaphylactic reaction to the MMR vaccine. The vaccine is to be administered in allergic children only under medical supervision.
- The influenza vaccine ("flu shot") contains egg protein. People who are sensitive to eggs, chicken with general symptoms such as a drop in blood pressure, significant wheezing, difficulty breathing, or urticaria should avoid getting the flu vaccine.
- The yellow fever vaccine also contains egg protein. Yellow fever is a major problem for people living or travelling to tropical South America or Africa. Tourists need to get yellow fever shots before entering the countries. Rather than skipping the vaccine, people who have a suspected allergy to eggs should get a series of two skin tests with the vaccine. If both tests are fine, proceed with the vaccine. If either test shows a reaction, a process of desensitization is followed.
If a person has gelatin allergy:
- Gelatin is a component in MMR, varicella, and yellow fever vaccines. People with severe allergies to gelatin should consider skin testing done before getting administered with a gelatin-containing vaccine.
- The gelatin used in vaccines is from pigs. People may not know that they may be exclusively allergic to pig gelatin, and not allergic to other sources of gelatin.
If a person is allergic to mercury:
- Mercury is an active ingredient in several vaccines. It is used to kill any live contaminants. In rare instances, the mercury can cause allergic reactions – from mild to severe. Mercury is mostly used for those vaccines which are stored in a multi-dose vial.
What type of adverse reactions occur on an allergic reaction to vaccines?
Adverse reactions to vaccines are highly varied, ranging from mild local reactions to fatal outcomes.
These reactions may be vaccination-induced reactions (due to the ingredients of the vaccine itself), reactions due to wrong storage or even incorrect administration.
Allergic children should not be excluded from the normal vaccination schedule as they are more susceptible to infection and viral diseases, which often play an aggravating role. Rubella, whooping cough and influenza usually aggravate respiratory allergies. Non-vaccination carries a risk of contracting serious diseases such as poliomyelitis, tetanus, etc.
Symptoms of vaccine caused allergic reactions:
- urticaria with angioedema
- local reactions
- persistent crying
- local reactions
- severe atopic dermatitis