Public Health England has published provisional data on the effectiveness of the influenza vaccine effectiveness in adults and children during the 2017/18 season.
The 2017/18 season was characterised by circulation of influenza B virus and influenza A(H3N2), with care home outbreaks and increased excess mortality particularly in the elderly.
As in previous seasons, influenza vaccine effectiveness was measured using a test-negative case control design through five primary care influenza sentinel swabbing surveillance schemes in England (two schemes), Scotland, Wales and Northern Ireland.
The provisional end-of-season adjusted influenza vaccine effectiveness estimates showed an adjusted all-age vaccine effectiveness of 15 per cent (95% CI -6.3 to 32.0) against laboratory-confirmed primary care consultations for influenza.
Vaccine effectiveness was 12.2 per cent (95% CI -16.8 to 34.0) in 18-64 year olds and 10.1 per cent (95% CI -54.8-47.8) in those aged 65 and older.
Effectiveness was 90.3 per cent (95% CI 16.4-98.9) against A(H1N1)pdm09 for 2-17 year olds receiving quadrivalent live attenuated influenza vaccine and 60.8 per cent (95% CI 8.2 to 83.3) against influenza B. There was no significant effectiveness against influenza A(H3N2).
These findings support the on-going roll-out of the paediatric vaccine programme, but also highlight the importance of effective interventions to protect the adult age groups, said Public Health England.
Next year, the vaccine composition is being updated. A new adjuvanted vaccine will be available for older adults and a quadrivalent flu vaccine for younger adults, which protects against both the main B strains and the two main flu A subtypes.