While immunizations are safe for the majority of people, patients occasionally have reactions to components of the immunizations. These people have formed IgE, which is a protein that mediates the allergic response, to specific parts of an immunization and develop a reaction when they receive the vaccine. Fortunately, patients often know about these allergies prior to receiving an immunization and can avoid having a reaction.
Types
As discussed by the American Academy of Pediatrics, vaccinations are made up of components that include viruses, bacteria, preservatives, additives and ingredients left over from creating the vaccine. The allergic reaction typically occurs in response to one of the additives rather than to the virus or bacteria component. The most common allergen in vaccinations is egg protein. It is possible, however, to be allergic to any component of the vaccination, including gelatin and small amounts of antibiotics that may remain in the vaccine.
Symptoms
Patients often develop localized reactions to vaccinations, such as soreness at the site of injection and a mild fever, that are not related to allergy. Symptoms of an allergic reaction include hives, nausea, vomiting, diarrhea, coughing, shortness of breath and syncope. These symptoms typically take place within an hour after a patient is exposed to the allergen. If these symptoms develop, immediate medical attention is required as medications that can reverse the reaction are needed.
Significance
As discussed by the Centers for Disease Control and Prevention (CDC), not all vaccinations contain egg protein, gelatin or antibiotics. Of these three components, egg protein is the most common allergen. Both the influenza vaccine and the vaccine for yellow fever contain egg protein, and the measles, mumps and rubella (MMR) vaccination contains an extremely small amount of egg protein. Some patients have such severe reactions to egg protein that they are unable to get vaccinated for influenza or yellow fever. This is an issue that can often be dealt with by an allergy specialist.
Diagnosis
Patients are typically aware of an allergy prior to receiving an immunization that contains the allergen. As discussed by the American College of Allergy, Asthma & Immunology (ACAAI), if an allergy to egg protein is suspected, a patient can undergo skin prick testing or blood testing to determine whether there is evidence of potential for an allergic reaction. Skin prick testing is a procedure done in an allergist's office. The allergist can then interpret and explain the results.
Treatment
While there is no cure for allergies to immunizations, an allergy specialist can often find a way to vaccinate safely. In some cases the vaccination can be given in graded amounts in an allergist's office where medical attention is readily available. If the vaccination cannot be given because of allergy, a patient may require prophylactic antibiotics or antivirals if he is exposed to the disease.
