A vaccine that could end the need for annual winter flu injections by offering lifelong protection against all strains of the virus has been developed by scientists.
The new universal flu vaccine, which researchers say will only need to be administered once, has been found to be effective against a number of different types of influenza virus, including the deadly avian flu and pandemic swine flu strains.
Flu viruses are highly changeable so elderly people and pregnant women, who are particularly vulnerable to the illness, are currently given new vaccinations each year to ensure they are protected.
Small-scale clinical trials on the new vaccine – known as Flu-v – have shown that it can significantly reduce infection and also cut the severity of symptoms.
Results of the trials will be presented at an international conference this week by SEEK, the London-based drug development company behind the vaccine.
Scientists who have been working on it are planning to conduct a large-scale clinical trial and hope to have a vaccine available for widespread use in three to five years time. If trials are successful, it would be offered to the NHS.
Professor John Oxford, a virologist at St Barts and Royal London Hospital and scientific director of Retroscreen Virology who conducted the clinical trial, said: “This vaccine clearly has a biological effect worthy of further investigation, particularly with respect to the broadness of the response.
“In the 2009 swine flu pandemic it was several months before a vaccine was available. A universal vaccine could end that wait and also reduce the need for people to have vaccines each year against seasonal flu.”
Vaccinations work by training the immune system to recognise viruses and mount a defence against them, but the flu virus constantly changes its outer “coat”, meaning it can evade detection.
With the new universal vaccine, however, scientists were able to identify a crucial part deep inside the influenza virus that does not change and is found in all strains.
By training the body’s immune system to recognise this part, infections from any strain of flu virus can be detected and combated by the immune system.
Drug development company SEEK, based in London, which developed the Flu-v vaccine, will present results from a Phase 2 clinical trial to experts at the Influenza Congress in Washington DC on Tuesday.
They will reveal that healthy volunteers given Flu-v showed less symptoms and had less virus in their blood streams when exposed to a mild strain of flu than those who had not been vaccinated.
Blood tests from the vaccinated volunteers also showed that their immune systems were active against a number of different types of flu, including bird flu and swine flu.
Gregory Stoloff, chief executive office of SEEK, said: “The trials we have undertaken suggest that we only need one shot of vaccine. We are going to explore dose levels and whether further a second dose will be more effective in future trials.”
Each year, winter flu epidemics can affect hundreds of thousands of people. Last year at least 600 died across the UK.
The NHS spends around £100 million each year on flu vaccinations. Elderly people over the age of 65 years old and pregnant women are offered the jabs for free.
In recent years many companies have also offered their employees annual flu vaccinations in a bid to reduce the burden the illness can have on their workforce.
Fears over new flu pandemic have resulted in many people getting vaccinated in the hope it may protect them.
Health officials, however, warn that a pandemic would be caused by an entirely new flu virus and so current vaccines are unlikely to offer protection.
In 2009 the H1N1 swine flu virus was declared a pandemic, with at least 50 people dying from swine flu in the UK last winter.
Health experts still fear that the deadly H5N1 avian flu virus could still combine with human flu viruses to create an even more deadly pandemic strain.
A number of researchers and drug companies have been working on techniques to produce a universal flu vaccine. BiondVax Pharmceuticals in Israel have also been conducting clinical trials on a similar vaccine to SEEK’s Flu-v.
Mr Stoloff added: “Our aim is for the flu vaccine to become more like the mumps and measles vaccine – where you only need it once and you get protection for a long time.”