People could be protected against bird flu within just a week provided they have received an earlier vaccination, claims a new study.

Data from the study, released in a letter to the New England Journal of Medicine sent by investigator Iain Stephenson, from University Hospitals Leicester, looks at an experimental pre-pandemic vaccine being developed by Novartis. The findings showed that people who received an earlier priming immunisation up to eight years before were still protected in seven days after receiving a booster jab.

This contrasts with the conventional approach whereby using two vaccinations once bird flu erupts means a six-week period before people are protected, time that might not be available if the virus spread quickly, Novartis notes. Dr Stephenson says that “with the pre-priming approach you could choose certain groups in advance, for instance health care workers, and almost vaccinate at leisure. Then you would only a need a week to provide protection.”

The vaccine contains the bird flu strain H5N1 and an adjuvant called MF59. In the study, the pre-vaccinated people received their first jab between 1999 and 2001 as part of earlier studies.

Two groups, involving around 60 patients in the UK, were involved in the study - one set who had been pre-vaccinated and another arm which had not. By day seven, 80% of the primed group showed a protective response after one shot of the adjuvanted vaccine compared to 20% in the un-primed group. The study noted that responses were seen even against viral strains not included in either vaccine.

Dr Stephenson said the data “highlight the potential for priming the public against an avian influenza of pandemic proportion with the MF59 adjuvant”. He added that regardless of which avian strain individuals are originally primed with, “they are quickly protected against a broad range of avian strains following their MF59-adjuvanted booster vaccine, even strains they were not initially inoculated against”.

Novartis says that the findings raise the prospect of a new debate about bird flu protection – away from a ‘stockpile and wait’ approach towards a “vaccinate now and then top up” policy. Dr Stephenson pointed out that the UK Government was already stockpiling bird flu vaccine but it was not clear yet how the logistics of getting this to people would be worked out if bird flu erupted suddenly.

“People need two vaccinations a month apart and there is a further two weeks before protective antibodies build up”, he said. If a bird flu pandemic erupted tomorrow, “it isn’t clear we would have six weeks to vaccinate people before it arrived in this country, even if the vaccine was stockpiled”, he concluded.