Experts develop sequence of instructions they say could help doctors evaluate risks
THURSDAY, Sept. 4 (HealthDay News) -- Vaccine safety experts say that almost all kids who are allergic to vaccines can receive vaccinations with close monitoring and a set of standard precautions.
Reporting in the September issue of Pediatrics, a team of experts led by the Johns Hopkins Children's Center put forth a step-by-step set of instructions -- an algorithm -- to help physicians evaluate and immunize children with known or suspected vaccine allergies.
Allergic reactions to vaccines are extremely rare -- with only one or two per million vaccinations -- but they can be serious and even life-threatening. Symptoms of a severe allergic reaction are usually immediate, may include hives, swelling, wheezing, coughing, low blood pressure, vomiting or diarrhea, and can lead to full-blown, life-threatening anaphylaxis.
To help pediatricians differentiate between these serious reactions to benign responses, the investigators analyzed the available evidence on vaccine safety and allergies.
"We cannot reiterate enough that the vaccines used today are extremely safe, but, in a handful of children, certain vaccine ingredients trigger serious allergic reactions," study author Robert Wood, chief of pediatric allergy and immunology at Hopkins Children's Center, said in a hospital news release. "For the most part, even children with known allergies can be safely vaccinated."
The new sequence of instructions developed by the research team is intended to be used for children who have already had or are at high risk for having allergic reactions to vaccines.
In these cases, the algorithm advises a workup by an allergist, who can perform skin prick testing or blood tests, to detect the presence of an allergy to a suspected allergen in the vaccine.
In many cases where a child is allergic to an allergen in a vaccine, an alternative form of the vaccine that is free of the allergen can be used. If an allergen-free vaccine is unavailable, many children can still be vaccinated under the supervision of a physician for several hours after the vaccination. Immunizations of children with known vaccine allergies should be administered at a clinic that is equipped to treat life-threatening reactions or in a hospital intensive care unit.
Physicians also have the option of checking the child for immunity to the disease that is being vaccinated against. If the child is already immune, further doses of the vaccine may not be necessary.
"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," investigator Neal Halsey, an infectious disease specialist at Hopkins Children's and a professor of international health at the Johns Hopkins University School of Public Health, said in the news release.
The American Academy of Family Physicians has more about childhood vaccines.
-- Krisha McCoy
SOURCE: Johns Hopkins Children's Center, news release, Sept. 2, 2008
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