Prevention of antigenically drifted influenza by inactivated and live attenuated vaccines.

ABSTRACT:

Background

The efficacy of influenza vaccines may decline during years when the circulating viruses have antigenically drifted from those included in the vaccine.

Methods

We carried out a randomized, double-blind, placebo-controlled trial of inactivated and live attenuated influenza vaccines in healthy adults during the 2004-2005 influenza season and estimated both absolute and relative efficacies.

Results

A total of 1247 persons were vaccinated between October and December 2004. Influenza activity in Michigan began in January 2005 with the circulation of an antigenically drifted type A (H3N2) virus, the A/California/07/2004-like strain, and of type B viruses from two lineages. The absolute efficacy of the inactivated vaccine against both types of virus was 77% (95% c

SUBMITTER: Ohmit SE 

PROVIDER: S-EPMC2614682 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature