The guidelines are intended for doctors and parents who are uncertain about vaccine safety in children who have already had or are at high risk for having allergic reactions to vaccines.
In such cases, the Hopkins-led group advises 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, researchers write.
"Vaccines save lives, and parents should know that children who have had allergic reactions after a vaccine are likely to have developed protection against infection as a result of the vaccination," says investigator Neal Halsey, M.D., an infectious disease specialist at Hopkins Children's, and professor of International Health at the Johns Hopkins University Bloomberg School of Public Health.
"Most children who have had an allergic reaction after a vaccine can still be vaccinated against other diseases safely and some can receive additional doses of vaccines they might have reacted to," Halsey adds.
Many children with known vaccine allergies who have low levels of protective antibodies and require more doses can be vaccinated safely under the guidelines. In some case
|Contact: Katerina Pesheva|
Johns Hopkins Medical Institutions