NEW YORK (Reuters Health) – Nearly all children with suspected or known hypersensitivity to vaccines can be safely immunized, US researchers contend, and in the September issue of Pediatrics, they describe an algorithm clinicians can use to ensure this.

“We cannot reiterate enough that the vaccines used today are extremely safe, but in a handful of children certain vaccine ingredients can trigger serious allergic reactions,” lead author Dr. Robert A. Wood, from Johns Hopkins Children’s Center in Baltimore, said in a statement. “For the most part, even children with known allergies can be safely vaccinated.”

Prior research has suggested that a true allergic reaction is seen in roughly 1 in 50,000 vaccinations with DTP. With other vaccines, reactions are even rarer, ranging from 1 in 500,000 to 1 in 1 million. Nonetheless, vaccine allergic reactions are relatively common given the large number of doses given to children each year.

The algorithm created by the team involves several steps to assist clinicians in evaluating and immunizing children with a suspected vaccine allergy. In children with a history of vaccine allergy or at high risk for hypersensitivity, the authors advise a work-up by an allergist.

According to the report, children with vaccine allergies can often be immunized with allergen-free formulations. When such formulations are not available, it may still be possible to immunize the child by pre-dosing with anti-allergy medications, such as antihistamines and corticosteroids.

Close monitoring for several hours following vaccination is a must in children with suspected vaccine allergy and should be done in a setting where life-threatening allergic reactions can be managed.

Alternatively, testing for protective antibodies may reveal that the child can defer vaccination or avoid it all together, the authors note.

Reference:
Pediatrics 2008;122:e771-e777.