A Perfect Storm: Impact of Genomic Variation and Serial Vaccination on Low Influenza Vaccine Effectiveness During the 2014-2015 Season.

ABSTRACT:

Background

The 2014-2015 influenza season was distinguished by an epidemic of antigenically-drifted A(H3N2) viruses and vaccine components identical to 2013-2014. We report 2014-2015 vaccine effectiveness (VE) from Canada and explore contributing agent-host factors.

Methods

VE against laboratory-confirmed influenza was derived using a test-negative design among outpatients with influenza-like illness. Sequencing identified amino acid mutations at key antigenic sites of the viral hemagglutinin protein.

Results

Overall, 815/1930 (42%) patients tested influenza-positive: 590 (72%) influenza A and 226 (28%) influenza B. Most influenza A viruses with known subtype were A(H3N2) (570/577; 99%); 409/460 (89%) sequenced viruses belonged to genetic clade 3C.2a and 39/460 (8%) t

SUBMITTER: Skowronski DM 

PROVIDER: S-EPMC4901864 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature