Skip to main content

Vanderbilt Children‘s Hospital study proves nasal spray flu vaccine works better than the shot in younger children

Mar. 6, 2007, 9:10 AM

A new study, co-authored by Kathryn Edwards, M.D., chief of the Division of Pediatric Clinical Research at the Monroe Carell Jr. Children‘s Hospital at Vanderbilt, suggests that the nasal spray flu vaccine is twice as effective as the flu shot in children 6 months to 5 years of age. The study, entitled “Live attenuated versus Inactivated Influenza Vaccine in Infants and Young Children” was published in a recent issue of the New England Journal of Medicine.

The nasal spray flu vaccine, licensed for children over 5 years of age as Flumist, has been available for a couple of years now. However, the vaccine has not been available for use in children under age 5 years or in anyone with a history of asthma-like symptoms. That disappointed some parents of younger children who had been awaiting an option to the injection form of the flu shot.

“We suspected the live, weakened virus might offer younger children more protection, and this study shows that it does,” said Edwards. “It works better in children because they have not been infected with the influenza vaccine many times before and they have not received vaccine many times before, so the live vaccine virus has a better “take” or works better in the young children than in the adults.”

Another compelling reason to expand the recommended age for use of the live vaccine is the possibility it may help to offset flu vaccine shortages that have happened almost annually for the last five years.

This study was quite large, taking place in 249 sites in 16 countries, involving 7,852 children who completed the trial. It directly compared the inactivated flu shot with the live attenuated nasal spray. While 55 percent fewer children got the flu when taking the nasal spray, there were more side effects like wheezing (3.8 percent versus 2.1 percent), and hospitalizations were more frequent among the 6- to 11-month-old infants who received the nasal flu vaccine. “The increase in wheezing in children younger than 1 year of age who received their first dose of the live vaccine is of concern,” Edwards said. “For that reason, the vaccine will not be licensed for children younger than 1 year of age or will not be licensed for use in children with underlying asthma.”

The success of the nasal spray in this study should lead to approval for younger children, perhaps as soon as next flu season, Edwards said.

Media Contact: Carole Bartoo, 322-7755

Recent Stories from VUMC News and Communications Publications

Vanderbilt Medicine
VUMC Voice