A universal vaccine to protect people from most strains of flu may be a step closer to reality.
Scientists say they have developed a vaccine which may only need to be given a few times over someone’s life, instead of a new one each year.
Current vaccines, offered during flu seasons, can become outdated quickly as the virus strains mutate and protect themselves from the drug.
But the new vaccine targets a part of the viruses which does not change between strains, meaning they could not become resistant in the same way.
And the researchers from the University of Pennsylvania say the body’s ability to stop flu actually gets stronger over time.
In the study on mice the authors say they were ‘blown away’ by the vaccine’s success and that ‘the sky’s the limit’.
Researchers at the University of Pennsylvania say of their new vaccine: ‘If it works in humans even half as well as it does in mice, then the sky’s the limit’
The US researchers began the study because, despite seasonal flu vaccines being widely available, the virus still infects millions of people each year.
Many are hospitalised and over 30,000 people die annually in the US because of the flu or complications caused by it.
The vaccine developed during the study successfully protected mice from various strains of influenza.
Bodies’ responses to infection also grow stronger over time after being vaccinated and react more fiercely after 30 weeks than after four weeks.
‘It could be something everyone uses in future’
‘If it works in humans even half as well as it does in mice, then the sky’s the limit,’ said study author Dr Scott Hensley.
‘It could be something that everyone uses in the future to protect themselves from the flu.’
LONG-TERM FLU JAB COULD BE ON NHS IN TWO YEARS
A single jab which protects against all strains of flu for up to a decade could be available on the NHS in just two years.
The results of a UK human trial announced in March suggest the FLU-v jab created by British company Imutex is more effective than existing vaccines which target only a few types of the virus.
Its creators claim it will end the scourge of flu globally, turning it into a mild illness rather than a killer.
It is likely to cost between £20 to £50 per person but will need to be given once every five to ten years.
Current vaccines target proteins on the virus surface, but regions of these proteins constantly change in a bid to fool the immune system.
The new jab has been created to target unchanging regions of the virus.
The trial involved 123 participants aged 18 to 60 being infected with the H1N1 swine flu virus and spending eight days in a room.
Eighty per cent were prevented from getting flu after having the jab.
The vaccine works by mimicking a flu infection and provoking the body’s immune system to learn how to attack the flu virus when it is in the body.
The vaccine attacks part of the virus which doesn’t mutate
Pennsylvania’s vaccine is different because, if you imagine the virus to be covered with proteins in the shape of mushrooms, it attacks the mushroom’s stalk.
Seasonal vaccines attack the head of the mushroom, but these can change shape when the virus strains mutate, meaning the vaccine becomes useless.
This is why seasonal vaccines must be given every year – because the nature of the virus has changed and a new vaccine is created.
However, the stalk always stays the same shape as the strains change, meaning the virus cannot become resistant to a universal vaccine, meaning injections would be needed only a few times over a person’s lifetime.
‘This vaccine was able to do something that most other candidate flu vaccines have not been able to do,’ said study co-author Dr Drew Weissman.
‘It was able to elicit protective responses against a region that offers broad protection.’
Scientists ‘blown away’ by vaccine’s effectiveness
Dr Hensley added: ‘When we first started testing this vaccine, we were blown away by the magnitude of the [immune] response.
‘The next step is to test this in primates and humans.’
As well as experiments on mice the scientists also tested the vaccine on ferrets and rabbits, and hope to begin human trials within two years.
Their research was published in the journal Nature Communications.