End of season influenza vaccine effectiveness in primary care in adults and children in the United Kingdom in 2018/19
Pebody RG., Whitaker H., Ellis J., Andrews N., Marques DFP., Cottrell S., Reynolds AJ., Gunson R., Thompson C., Galiano M., Lackenby A., Robertson C., O'Doherty MG., Owens K., Yonova I., Shepherd SJ., Moore C., Johnston J., Donati M., McMenamin J., de Lusignan S., Zambon M.
© 2019 2018/19 was the first season of introduction of a newly licensed adjuvanted influenza vaccine (aTIV) for adults aged 65 years and over and the sixth season in the roll-out of a childhood influenza vaccination programme with a quadrivalent live attenuated influenza vaccine (LAIV). The season saw mainly A(H1N1)pdm09 and latterly A(H3N2) circulation. End-of-season adjusted vaccine effectiveness (aVE) estimates against laboratory confirmed influenza infection in primary care were calculated using the test negative case control method adjusting for key confounders. End-of-season aVE was 44.3% (95% CI: 26.8, 57.7) against all laboratory-confirmed influenza; 45.7% (95% CI: 26.0, 60.1) against influenza A(H1N1)pdm09 and 35.1% (95% CI: −3.7,59.3) against A(H3N2). Overall aVE was 49.9% (95%CI: −13.7, 77.9) for all those ≥ 65 years of age and 62.0% (95% CI: 3.4, 85.0) for those who received aTIV. Overall aVE for 2–17 year olds receiving LAIV was 48.6% (95% CI: −4.4, 74.7). The paper provides evidence of overall significant influenza VE in 2018/19, most notably against influenza A(H1N1)pdm09, however, as seen in 2017/18, there was reduced, non-significant VE against A(H3N2). aTIV provided significant protection for those 65 years of age and over.