Despite this decrease in use, vaccine efficacy was evident: It was 64.7% overall and 85.8% among children younger than 2 years, the investigators said (Pediatrics 2014;133:e1218-25).
Even among children who did not receive the full schedule of vaccine doses, vaccine efficacy exceeded 81%. "This study provides the strongest evidence to date supporting the effectiveness of the trivalent influenza vaccine in children younger than 2 years of age," Dr. Blyth and his associates said.
This study was funded by the Western Australian Department of Health. The vaccine was provided by Sanofi Pasteur and CSL Biotherapies. Dr. Peter C. Richmond reported past ties to Baxter and GlaxoSmithKline. Dr. Blyth and the remaining associates reported no relevant financial conflicts of interest.