The overall efficacy of flu vaccinations in 2014 to 2015 fell to 34%, according to a new report published by Public Health England (PHE).
In people aged under 18 years, the vaccination was effective against 35% of cases of influenza A, while it was 100% effective against influenza B. In adults, the efficacy of the vaccine was 29.3% for influenza A, and 46.3% against influenza B. Estimates made in the middle of the flu season calculated the efficacy of the vaccine overall to be approximately 3%. However, due to a shift in the prevalence of certain strains of influenza circulating, the figure rose to 34%.
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.’
Professor Cosford said: ‘While it is 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.’
In the 2014 to 2015 period all children aged two, three and four were given the Fluenz nasal vaccination against influenza. Older children in primary and secondary schools were given the vaccination in certain pilot areas. The vaccination programme against influenza in children began in 2013.