At-risk groups may no longer need to be vaccinated every year, according to Professor David Salisbury, DoH director for immunisation. This would be possible, he said, if data show that GSK's swine flu vaccine offers long-term protection.
GSK's Pandemrix vaccine includes an adjuvant, designed to reduce the amount of antigen needed in manufacture.
Adjuvants also help vaccines provide some degree of cross-protection. They could help improve provide protection offered by a vaccine even if the virus 'drifts', mutating into a different strain.
Professor Salisbury said last week that the ability to protect against drifted strains opens the possibility of a ‘completely different strategy' for protecting against seasonal flu.
‘Whether we will need to protect every year against seasonal flu for all at-risk groups, is something we have to get some research on,' he said.
‘We need research to tell us whether protection will last for more than one season against a drifted strain,' he added.
‘We ought to be able to protect the elderly much better, with these more immunogenic vaccines. We may be entering into a new era for seasonal flu based on our experiences.'
He predicted that the H1N1 swine flu strain would be added to next year's trivalent vaccine. But he said there would also need to be discussion about whether there would be a place for a bivalent vaccine, without H1N1. Because so many people in at-risk groups would have received the swine flu vaccine this season, they may not need to receive it again next year, he suggested.
A spokeswoman for GSK said that the company had begun trials of an innovative vaccine for seasonal influenza containing an adjuvant similar to the one pioneered for the pandemic vaccine Pandemrix.
Adjuvant systems work in tandem with the antigens to help stimulate a stronger immune response in vaccinated individuals, she said. Addition of an adjuvant system to influenza antigens can give a better immune response as compared to a vaccine without adjuvant.
But, she added, results from the seasonal vaccine study would not be ready until 2011 and the company would then need to apply for approval of the vaccine.
'Once we have these results we will still need to file these with the appropriate authorities and await their decision,' she said.