Evidence for the safety and efficacy of influenza vaccines in the over 65s is poor, despite their use being recommended for older people for the past 40 years, according to the latest review from the Cochrane Library.
The study argues that adults aged 65 and over “are some of the most vulnerable during influenza season and a priority for vaccination programmes” but very few systematic reviews of the effectiveness of jabs in this group have ever been carried out. The researchers conducted “a thorough search of studies based on previous vaccine trials”, noting that while randomised controlled trials (RCTs) “are often considered the “gold standard’,” only one out of 75 studies included in their review helped them identify “real” outcomes.
In other words, the researchers say, this was the only RCT that used influenza cases as an outcome, as opposed to surrogate outcomes such as measurements of influenza antibodies in the blood. “All the other studies included in the review were deemed of low quality and open to bias”, they add.
Lead researcher Tom Jefferson of the Cochrane Collaboration in Rome said that limited reliable evidence from the studies suggests that the effectiveness of influenza vaccines is modest at best. He went on to say that “our estimates are consistently below those usually quoted by economists and in decision making” and “until we have all available evidence, it is hard to reach any clear conclusions about the effectiveness of influenza vaccines in older people”.
In the UK, 12,000 people die of flu-related illnesses each year, according to Government data, but this figure has been disputed. Also estimates on the cost of vaccination for the elderly vary from £110-£150 million.
Dr Jefferson added that “as the evidence is so scarce at the moment, we should be looking at other strategies to complement vaccinations. Some of these are very simple things like personal hygiene, and adequate food and water”. He suggests that “we need to undertake a high-quality, publicly-funded trial that runs over several seasons to try to resolve some of the uncertainties we’re currently facing”.
Dr Jefferson is also one of the authors of a second review, focusing on the flu vaccination of healthcare staff who work with the elderly. These results were also inconclusive, with each of the four trials included in the review “being of inadequate quality and reaching implausible conclusions”.
