News Update: Single dose of H1N1 vaccine is safe and effective in children

A single dose of the H1N1 vaccine may be enough to prevent infection in infants and children, according to a new study.

An article published online ahead of print in the Journal of the American Medical Association reported on the results of a randomized, observer-blind, multicenter, parallel-group study that assessed the efficacy of an inactivated, split-dose 2009 influenza A(H1N1) vaccine in 370 children aged 6 months to <9 years. Study patients were treated with 2 injections (21 days apart) of either a 15- or 30-mcg dose of the vaccine. A total of 92.5% (95% confidence interval [CI], 87.6%-95.6%) of patients treated with the 15-mcg dose and 97.7% (95% CI, 94.2%-99.1%) of patients treated with the 30-mcg dose had antibody titers of at least 1:40 after the first dose of vaccine. All patients had achieved antibody titers of at least 1:40 after the second vaccine dose.

Two serious adverse events were reported among study patients, including a case of fluctuating fever and a case of viral gastroenteritis. Other adverse events were mild-to-moderate in severity.