Serious allergic reactions to vaccines are extremely rare - one or two per million vaccinations, according to estimations - but when they happen, such episodes can be serious. With close monitoring and a few standard precautions, nearly all children with known or suspected vaccine allergies can be safely immunised, according to a recently published paper. The authors offer pediatricians a step-by-step tool for quickly identifying affected children, and a guide to safely immunise these.
Combing through available evidence on vaccine safety and allergies, the team developed a sequence of instructions - an algorithm - that prompts physicians one step at a time on how to evaluate and immunise children with known or suspected vaccine allergies.
In such cases, the scientists advise a workup by an allergist, including skin prick testing-a prick on the skin or an injection under the skin with a small dose of vaccine or the suspected allergen from the vaccine-or blood tests that would detect the presence of characteristic antibodies that patients develop to allergens, such as antibodies to gelatin or egg proteins used in several common vaccines.
In many cases, allergic children can be vaccinated using alternative forms of a vaccine that are free of the allergen. Even if allergen-free formulations are unavailable, many children can still be vaccinated and remain under physician supervision for several hours after vaccination.
Another option is testing the child to check for immunity. If blood tests show the child has already developed protective antibodies, it may be ok, at least temporarily, to withhold further doses of the vaccine.
Most children with known vaccine allergies who have low levels of protective antibodies and require more doses can still be vaccinated safely. For example, some of these children could be given anti-allergy medications, such as antihistamines and corticosteroids, before vaccination to help ward off or lessen the allergic reaction.
MEDICA.de; Source: Johns Hopkins Medical Institutions