Several prominent media articles have suggested that the flu vaccination programme for the over 65s is not worthwhile. Rachel Jordan from the University of Birmingham and Jeremy Hawker from the Health Protection Agency review the evidence surrounding the ongoing controversy.
The annual influenza vaccination campaign is one of the most successful public health programmes in the UK, with 78% of people over 70 receiving the jab, the highest in Europe.
However, according to the authors, it is notoriously difficult to find out the full effectiveness of the influenza vaccine. For instance, the vaccine may not fully match the strain of a particular year, influenza seasons vary in timing and strength, and few studies measure influenza specific outcomes.
Previous trials have shown that the vaccine is effective in preventing influenza in those over 60. But recently, some researchers have questioned the validity and plausibility of findings for other less specific benefits provided by the vaccine, such as a reported reduction in hospital admissions for influenza and pneumonia by 27% and particularly all cause deaths by 48%. This would imply that most deaths in winter were due to influenza.
Large, routinely-collected datasets analysed in some of these studies had limited patients' details which did not include functional status, disease severity, or smoking status. Other studies which tried to allow for this, have shown benefits to be smaller but significant, whereas one reported no clear effect on all cause deaths. Influenza activity was, however, relatively low in several of these years.
Despite these methodological problems and disagreements, most experts agree that although more evidence is needed on the precise effectiveness of the vaccine, it has some benefit and the vaccination programmes should continue, say the authors.
"Influenza causes substantial mortality and morbidity in older people, and even if the more general all cause mortality benefit may be lower than previously thought, the current vaccine programme offers older people valuable protection against illness, hospital admissions, and mortality specific to influenza, should they be exposed this winter", say the authors.
They conclude by calling for resources to develop more effective vaccines, better forms of delivery of the vaccine for the elderly, and ensuring that more healthcare workers who come into contact with elderly people are vaccinated.