Press releases Monday 5 October to Friday 9 October 2009

Please remember to credit the BMJas source when publicising an article and to tell your readers that they can read its full text on the journal's website (http://www.bmj.com).

(1) Seasonal vaccine offers some protection against swine flu
(1) Common mental disorders may be linked to an increased risk of obesity
(3) Four out of 10 back pain sufferers will recover within a year
(4) Including boys in HPV vaccination programmes would not offer value for money
(5) Screening all patients for MRSA "unethical" says expert
(6) Collaborative requesting does not increase consent for organ donation
(7) Four out of 10 back pain sufferers will recover within a year

(1) Seasonal vaccine offers some protection against swine flu
(Research: Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City)
http://www.bmj.com/cgi/doi/10.1136/bmj.b3928
(Editorial: The future of influenza vaccines)
http://www.bmj.com/cgi/doi/10.1136/bmj.b4014

The 2008-2009 seasonal flu vaccine (trivalent inactivated vaccine, TIV) provides some protection against swine flu, particularly the most severe forms of the disease, according to preliminary research published today on BMJ.com.

However, the authors emphasise that the results should be considered cautiously "and in no way indicate that seasonal vaccine should replace vaccination against pandemic influenza A/H1N1 2009."

In June 2009, the emergence of this new flu virus led the World Health Organisation to raise the level of influenza pandemic alert from phase three to phase six. By July 2009, 122 countries reported almost 100,000 confirmed cases of swine flu.

This study, led by Dr Jose Luis Valdespino from Mexico, investigated the link between the 2008-9 seasonal flu vaccine with cases of influenza A/H1N1 during the epidemic in a speciality hospital in Mexico City.

The authors say the reason the seasonal vaccine offers some protection is because it boosts existing antibodies in individuals who have previously been exposed to a similar flu virus, either by infection or vaccination.

Valdespino and colleagues compared the health outcomes (hospitalisation, mechanical ventilation and death) of 60 patients with swine flu and 180 control patients with other diseases. Both groups of patients informed the authors directly, by telephone or via a close relative whether they had received the 2008-9 seasonal flu vaccine.

The results show that the uninfected participants were significantly more likely to have received the seasonal flu vaccine and suggest that it protected them against particularly severe forms of swine flu. However the authors say the results must be taken in context and argue that given the small sample size "it will be key to conduct similar studies in other settings to confirm or refute our results."

In an accompanying editorial, Dr Menno de Jong from the Academic Medical Centre of the University of Amsterdam concurs with Dr Valdespino that the results do not mean that there is no need for a specific vaccine against swine flu.

Dr de Jong also raises the issue of vaccine production and says that vaccines may not be available in time, even in countries that have procured sufficient quantities, so that "vaccinated people may be protected only after the peak of the pandemic has passed." He added that "to protect against seasonal and pandemic strains, vaccines and vaccine production need to improve."

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