A super drug that protects against all of the most deadly types of flu has been developed by scientists. A single injection of the anti-viral medicine can fight off everything from a common winter virus to a life-threatening strain of bird flu, researchers say.

The breakthrough brings closer the Holy Grail of influenza treatment, a one-shot vaccine that gives lifelong protection against every imaginable type of the virus. Researchers believe the drug, which uses man-made antibodies, could be available in less than five years. A vaccine based on the technology could follow soon after.

Flu experts say it is only a matter of time before Britain is struck by another major flu pandemic similar to the one which killed millions of people in 1918. They are most concerned about the deadly H5N1 strain of avian flu which has killed 200 people and led to the deaths of millions of birds. (Snip)

The new drug has the potential to save thousands, if not millions, of lives during a major pandemic. Stockpiles of the drug could be used to keep influenza at bay during the four to six months it would take to develop a new vaccine. It works by targeting an ‘Achilles Heel’ on the flu virus that scientists have previously overlooked. (Snip)

‘However, I don’t think it’s realistic at the moment to imagine making this antibody as a treatment  – I think it would cost about £10,000 per month to protect an adult. ‘But the fact that it is possible for antibodies to be so broad raises the possibility that a vaccine could be made that would work from one year to the next – as well as  work against as yet undiscovered types of flu. ‘If so, we could imagine a vaccine that works against all winter flu strains and also protects against unknown future pandemics. That would be a major breakthrough.’

Antibodies work by seeking out proteins on the surface of a virus and then attaching themselves. The virus is disabled and unable to invade the  body’s cells to make copies of itself. Under an electron microscope, proteins on the surface of a flu virus look a little like lollipops. Most vaccines and antibodies target the large round head of the proteins.However, this part of a protein mutates very easily – and changes from year to year. That’s why new vaccines are needed each flu season.

Instead, the American scientists looked for antibodies that latch onto the thinner ‘shaft’ of the lollipop-shaped protein.  This part of the virus is much less likely to mutate and is identical in a huge range of flu viruses. After screening a library of tens of billions of different antibodies, they found 10 that would work, (Snip) The protein targeted was called hemagglutinin, or HA.