Here in the UK it’s cold, and the cold weather tends to bring with it an upsurge in the rates of viral infections such as the common cold and flu. It has been suggested that one reason such infections surge in the winter is because we’re more likely to be cooped up with other people, spreading infections among us. However, another mechanism that might explain this phenomenon relates to vitamin D: this nutrient has anti-infective properties and its levels usually fall in the winter, perhaps increasing our risk of succumbing to infection. I wrote about this a couple of years ago here. I also recently suggested that optimising vitamin D might help keep infections at bay (I’ve not had a single infection since I started supplementing with vitamin D about a year ago).
Now fresh concerns have been raised regarding the appropriateness of flu vaccination policy in the form of a review of relevant evidence performed my scientists from the Cochrane Collaboration (an international group of scientists specialising in systematic reviews of health-related interventions) . The review focused on flu vaccination in individuals aged 65 and older (deemed to be the ones most likely to benefit from vaccination, as this group is at increased risk of complications of flu including death). You can download a pdf of the review here.
The reviewers identified 75 vaguely-relevant studies, but only one of these was deemed especially relevant in that it was a ‘randomised controlled trial’ (generally regarded as the most relevant and useful test of a medical treatment) which compared outcomes in vaccinated and unvaccinated individuals using currently available vaccines. This study, apparently, yielded some evidence that vaccination helped protect against the flu, but it was big enough to tell us whether this translated into a reduced risk of complications. This is important because one could argue that getting the flu is neither here nor there really. What is really important is whether this then leads to an enhanced risk of things like pneumonia and death (as I mentioned above, this is particularly important in the elderly).
The authors concluded that “The available evidence is of poor quality and provides no guidance regarding the safety, efficacy or effectiveness for people aged 65 years or older.” In other words, flu vaccination in the elderly is a shot in the dark.
Some of you may be surprised that governments institute and fund health policies for which there is little or no evidence of benefit. Don’t be – not so long ago we learned that the UK Government’s doling out of a anti-flu prescription medication (Tamiflu) over the phone wasn’t based on any decent science either.
1. Jefferson T, et al. Vaccines for prevent influenza in the elderly (review). The Cochrane Library 2010 (issue 2)