Your Family Physician

One dose of live attenuated influenza vaccine (LAIV) administered intranasally provides significant protection against influenza in previously unvaccinated young children, while two doses of the vaccine provides additional protection, according to the results of a study published in the May issue of the Pediatric Infectious Disease Journal.

"Beginning with the 2008-2009 influenza season, the Advisory Committee on Immunization Practices of the U.S. Centers for Disease Control and Prevention recommends routine vaccination against influenza for all children 6 months to 18 years of age," note Dr. William C. Gruber, of Wyeth Vaccines Research, Pearl River, New York, and colleagues.

The researchers prospectively examined the efficacy and safety of one versus two doses of LAIV in 3200 previously unvaccinated children aged 6 to <36>

Subjects were randomly assigned to one of four regimens: two doses LAIV, one dose LAIV, excipient placebo, or saline placebo.

Vaccine efficacy versus placebo among those who received two doses of LAIV was 73.5% against antigenically similar strains. Efficacy among those who received one dose of the vaccine was 57.7%.

LAIV was significantly effective against acute otitis media, but not lower respiratory tract infection, Dr. Gruber and colleagues found.

LAIV was well tolerated, and the safety and tolerability of the vaccine were consistent with previous studies, the team reports.

Furthermore, the team observed that protection after two doses of the vaccine persisted into the next season without revaccination.

They conclude that the findings "provide support for increased use of LAIV" in children 2 years of age or older.

Pediatr Infect Dis J. 2009;28:365-371.

Source : http://www.medscape.com/viewarticle/703489?src=mpnews&spon=34&uac=133298AG