News story

Final flu vaccine effectiveness data published

New research confirms the overall effectiveness of the 2014 to 2015 flu vaccine.

The child flu vaccine (fluenz) used in last year’s flu season provided good protection against circulating strains of influenza B according to a new Public Health England (PHE) study published in Eurosurveillance.

For those aged under 18 years:

  • effectiveness of the vaccine against influenza A was 35%
  • effectiveness of the vaccine against influenza B was 100%

In last year’s flu season, all children aged 2, 3 and 4 were offered the nasal spray child flu vaccination Fluenz, along with primary and secondary school aged children in select pilot areas across the UK.

Today’s report, which is an update on previous mid-season figures on vaccine effectiveness, also found that the 2014 to 2015 adult flu vaccine used in the UK was 34% effective against the circulating strains of flu. Lower estimates of the effectiveness were calculated mid-season at 3%, however a shift in the dominant circulating strains occurred throughout the rest of the flu season. The final results showed:

  • effectiveness of the adult flu vaccine against influenza A was 29.3%
  • effectiveness of the adult flu vaccine against influenza B was 46.3%

Professor Paul Cosford, PHE’s Director for Health Protection and Medical Director, said:

In recent years, we have typically seen around 50% (ranging from 25 to 70%) effectiveness for the flu vaccine in the UK, and there has generally been a good match between the strains of flu in the vaccine and those that subsequently circulate. However, last year we saw a slightly lower vaccine effectiveness than usual.

Whilst it’s not possible to fully predict the strains that will circulate in any given season, flu vaccination remains the best protection we have against an unpredictable virus which can cause severe illness and deaths each year among at-risk group. These include older people, pregnant women and those with a health condition, even one that is well managed.