Low effectiveness of seasonal influenza vaccine in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2014/15 mid–season results
Pebody RG., Warburton F., Ellis J., Andrews N., Thompson C., Wissmann BV., Green HK., Cottrell S., Johnston J., De Lusignan S., Moore C., Gunson R., Robertson C., McMenamin J., Zambon M.
In 2014/15 the United Kingdom experienced circulation of influenza A(H3N2) with impact in the elderly. Midseason vaccine effectiveness (VE) shows an adjusted VE of 3.4% (95% CI: −44.8 to 35.5) against primary care consultation with laboratory-confirmed influenza and −2.3% (95% CI: −56.2 to 33.0) for A(H3N2). The low VE reflects mismatch between circulating viruses and the 2014/15 northern hemisphere A(H3N2) vaccine strain. Early use of antivirals for prophylaxis and treatment of vulnerable populations remains important.