Washington: Close monitoring and a few precautions can help vaccinate children with known or suspected allergies, according to John Hopkins Children's Centre team.

The team offered paediatricians a step-by-step tool for quick identification and a much-needed guide to immunisation of children with allergic reactions, they said.

"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," said Robert Wood, Co-author of the paper and Chief of Paediatric Allergy and Immunology at Hopkins Children's.

Serious allergic reactions to vaccines are extremely rare - one or two per million vaccinations, according to some estimates - but when they happen, such episodes can be serious, even life-threatening, making it critical for paediatricians to instantly spot true allergic reactions and differentiate them from more benign non-allergic responses, investigators said.

It is also crucial that paediatricians design a safe immunisation plan for children with confirmed vaccine allergies. Children who have had one allergic reaction are believed to be at a higher risk for future reactions, typically more serious than the first.

Given recent outbreaks of vaccine-preventable infections like measles, mumps and whooping cough in the US, and measles and polio overseas, it is essential to safely vaccinate as many children as possible, they said.

Combing through available evidence on vaccine safety and allergies, the Hopkins-led team developed a sequence of instructions - an algorithm - that prompts physicians one step at a time on how to evaluate and immunize children with known or suspected vaccine allergies.

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.

"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," said investigator Neal Halsey, an infectious disease specialist at Hopkins Children's.

These findings appeared in September issue of Paediatrics. IANS