The H1N1 (“Swine flu”) vaccination programme introduced in Scotland in October 2009 had a positive effect in reducing the number of hospital admissions and deaths as a result of H1N1 infection, according to an Article published Online First in The Lancet Infectious Diseases. The study was funded by the National Institute for Health Research Health Technology Assessment (NIHR HTA) programme.
The researchers used detailed data collected by Scottish health agencies to examine the effect of H1N1 vaccination on the Scottish population. Vaccination showed clear association with protection against pandemic influenza, and a 20% reduction in hospital admissions due to influenza-related disorders. While only 16% of the people studied were vaccinated during the study period, the researchers found that 77% of people who had been vaccinated avoided contracting the H1N1 virus.
When analysing rates of hospital admissions, the researchers took into account admissions not only for flu-like symptoms, but also the related conditions of pneumonia, chronic obstructive pulmonary disease (COPD), and cardiovascular-related disease, reflecting the fact that flu can often complicate (or be complicated by) these pre-existing conditions in vulnerable patients.
According to lead author Dr Colin Simpson, Senior Research Fellow at the University of Edinburgh, “Our findings help strengthen the international evidence base for the effectiveness of H1N1 vaccination programmes and the future distribution of pandemic influenza vaccines. Policy makers ought to be encouraged that our vaccine estimates obtained are similar to those reported for seasonal influenza. However, despite the best efforts to encourage the most vulnerable to be vaccinated, there were low rates of uptake in the very young and pregnant women who were most susceptible to the pandemic.”
In a linked Comment, Professor John Oxford of the Blizard Institute of Cell and Molecular Science, Bart’s and the London, UK, described the study as demonstrating “the inherent scientific strength of the NHS”, pointing out that very few countries’ health systems allow for the integrated and accessible data recording that made this study possible.
While urging further research to confirm the findings, Professor Oxford suggests that lessons from this study could be used to minimise the impact of the next major flu outbreak: “The study reaffirms the positive consequences of a rapidly formulated influenza vaccine in the case of a pandemic. The next step is to start examining how we could use similar methods to those used in this study, but in real time, which would allow authorities to prepare themselves and distribute vaccine appropriately.”
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