title: Effectiveness of seasonal influenza vaccine in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2014/15 end of season results.
abstract: The 2014/15 influenza season in the United Kingdom (UK) was characterised by circulation of predominantly antigenically and genetically drifted influenza A(H3N2) and B viruses. A universal paediatric influenza vaccination programme using a quadrivalent live attenuated influenza vaccine (LAIV) has recently been introduced in the UK. This study aims to measure the end-of-season influenza vaccine effectiveness (VE), including for LAIV, using the test negative case-control design. The overall adjusted VE against all influenza was 34.3% (95% confidence interval (CI) 17.8 to 47.5); for A(H3N2) 29.3% (95% CI: 8.6 to 45.3) and for B 46.3% (95% CI: 13.9 to 66.5). For those aged under 18 years, influenza A(H3N2) LAIV VE was 35% (95% CI: -29.9 to 67.5), whereas for influenza B the LAIV VE was 100% (95% CI:17.0 to 100.0). Although the VE against influenza A(H3N2) infection was low, there was still evidence of significant protection, together with moderate, significant protection against drifted circulating influenza B viruses. LAIV provided non-significant positive protection against influenza A, with significant protection against B. Further work to assess the population impact of the vaccine programme across the UK is underway.
authors.affiliation: Public Health England, England, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Pebody
authors.forename: Fiona
authors.initials: F
authors.lastname: Warburton
authors.forename: Nick
authors.initials: N
authors.lastname: Andrews
authors.forename: Joanna
authors.initials: J
authors.lastname: Ellis
authors.forename: Beatrix
authors.initials: B
authors.lastname: von Wissmann
authors.forename: Chris
authors.initials: C
authors.lastname: Robertson
authors.forename: Ivelina
authors.initials: I
authors.lastname: Yonova
authors.forename: Simon
authors.initials: S
authors.lastname: Cottrell
authors.forename: Naomh
authors.initials: N
authors.lastname: Gallagher
authors.forename: Helen
authors.initials: H
authors.lastname: Green
authors.forename: Catherine
authors.initials: C
authors.lastname: Thompson
authors.forename: Monica
authors.initials: M
authors.lastname: Galiano
authors.forename: Diogo
authors.initials: D
authors.lastname: Marques
authors.forename: Rory
authors.initials: R
authors.lastname: Gunson
authors.forename: Arlene
authors.initials: A
authors.lastname: Reynolds
authors.forename: Catherine
authors.initials: C
authors.lastname: Moore
authors.forename: David
authors.initials: D
authors.lastname: Mullett
authors.forename: Sameera
authors.initials: S
authors.lastname: Pathirannehelage
authors.forename: Matthew
authors.initials: M
authors.lastname: Donati
authors.forename: Jillian
authors.initials: J
authors.lastname: Johnston
authors.forename: Simon
authors.initials: S
authors.lastname: de Lusignan
authors.forename: Jim
authors.initials: J
authors.lastname: McMenamin
authors.forename: Maria
authors.initials: M
authors.lastname: Zambon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D017589:Immunization Programs; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D009981:Influenza B virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control* / Q000821:virology; D007753:Laboratories; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D012141:Respiratory Tract Infections / Q000517:prevention & control / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012621:Seasons; D018571:Sentinel Surveillance; D006113:United Kingdom / Q000453:epidemiology; D014611:Vaccination / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines
keywords: UK; influenza; primary care; vaccine effectiveness