Date: Thu, 25 Mar 2004 09:15:02 -0800

Flu vaccine may be linked with asthma in infants

Last Updated: 2004-03-24 16:19:03 -0400 (Reuters Health)

By David Douglas

NEW YORK (Reuters Health) - A study of more than 9,000 children and
adolescents indicates that the use of the nasal influenza vaccine (FluMist)
is generally safe. However, questions still remain about the risk of
reactive airway disease in certain children under the age of 3 years.

As researcher Dr. Steve Black told Reuters Health, "there was a suggestion
that (such) children vaccinated with (FluMist) were at increased risk for
medical visits for asthma within 6 weeks following vaccine as compared to
controls. However, children with asthma prior to vaccination, overall, had
a lower risk of asthma visits as compared to controls."

In the Pediatric Infectious Disease Journal, Black of the Kaiser Permanente
Vaccine Study Center in Oakland, California, and colleagues note that they
came to these conclusions after a trial of the nasal flu vaccine in
children between 1 and 17 years old.

All received at least one dose of vaccine or placebo. Those 8 years or
younger received a second dose 28 to 42 days later. All children were
followed for 42 days after each vaccination.

Following evaluation of 9,689 children, there appeared to be no association
between vaccination and acute respiratory tract infections, systemic
bacterial infection, acute GI complaints, and those potentially associated
with influenza.

However, in children aged 18 to 35 months there was a four-fold increased
risk of reactive airway disease.

Thus, continued Dr. Black, "our conclusion was that the risk of asthma
following (nasal flu vaccination) in children less than three years old
needed further evaluation prior to the use of the vaccine in that age group."

They theorize that if this increased risk is confirmed in another study, it
may be that these children have never been exposed to an influenza virus
"and might respond to this vaccine differently because of this."

SOURCE: Pediatric Infectious Disease Journal, February 2004