Swine flu vaccination

A swine flu vaccine has been available since November, with health care workers and people in various high risk groups (e.g. pregnant women and those with underlying health conditions) initially given priority. The campaign requires GPs to identify patients for vaccination, and to arrange for them to attend their surgery - quite an organisational effort.

So, has it worked? We've been asking flusurvey participants to tell us whether or not they've been vaccinated, and why (or why not - it's just as important to know why people choose not to be vaccinated).

We've looked at people who, according to the backgroundquestionnaire, are in a "high risk" group (i.e. have some underlyinghealth condition) and at health care workers. Uptake isreasonably good in both these groups (around 50%), but is unsurprisingly low in the rest of thepopulation.

For the vaccine to make a difference, it needed to be given outquickly. Above, we see that vaccination steadily increased throughNovember and early December - certainly not as quickly as we would have liked. 

Lastly, we asked people why they chose to have or to avoid a vaccine. Sensibly, people choose to be vaccinated to protect themselves and those around them, while those in high risk groups also opt for the vaccine because of their health condition, although (not surprisingly) our definition of a high risk group, made before the pandemic kicked off, didn't always tally with the observed patterns.

Some people report concerns about vaccine side-effects (though initial information indicates that the vaccine is a pretty safe one), but in general people choose not to be vaccinated because they are not in swine flu high-risk groups.

Because of the timing of the vaccination campaign, our results show that it didn't happen quickly enough to make much difference to the epidemic as a whole. However, because vaccination was targeted at those who would get the most benefit, it probably protected vulnerable people during the later part of the epidemic.

It's clear that there are important lessons to be learnt from all of this about how to rapidly vaccinate a population - flusurvey data will continue to be used to help the health authorities understand what worked (and what didn't) and why.

Seasonal flu vaccination and its impact on swine flu

A significant fraction of the population (particularly the elderly) seemed to have some protection against swine flu, probably due to previous exposure to similar viruses. As expected, the elderly were much more likely to be vaccinated for seasonal flu (left). Our results suggested that the seasonal flu vaccine might also provide some protection, even though it was not designed to protect against the strain that causes swine flu. Those who had the seasonal flu vaccine seemed less likely to get infected. Other factors may have been involved as well, but these data are certainly suggestive.