Coming soon: A once-in-a-lifetime flu jab!

A team at the National Institute of Health in Maryland is developing the new vaccine which it claims would fight off all strains of the disease -- from the winter flu to deadly pandemic viruses.

Described as the "holy grail" of flu research, the scientists say that the jab would be available within five years' time, the 'Daily Mail' reported. In fact, the new drug uses DNA to trick the body's immune system into producing antibodies against the protein's base instead -- the "lollipop stick". And, just one or two shots could provide lifelong protection, say the scientists.

Unlike the head, the "stick" changes little from strain to strain, meaning one vaccine should protect against multiple strains of the virus. Dr Gary Nabel, the institute's director of vaccine research, used the DNA from the protein to trick animals' immune systems into producing antibodies that seek out and destroy the bug.

The team then gave a "booster shot" of a harmless flu or cold virus to ratchet up the immune response. This primer- booster approach killed off a flu virus from 2007 and one from 1934, despite the DNA coming from a strain circulated in 1999.

Mice and ferrets both fought off potentially deadly flus with the help of the double jab. The vaccine was also effective against bird flu. Safety trials have begun on people and its effectiveness could be tested on patients by 2013.

If the vaccine is as safe and powerful as the research team hope, it should be in widespread use by 2015. Dr Nabel said that a universal jab would remove the annual race to outwit the virus by formulating a jab that protects against the latest mutations.

"Every year we try to predict which virus will circulate the next year. If we predict correctly and make a vaccine that's a good match, we are ok. But maybe once every three years a new strain crops up or one that is just completely different from what was predicted.

"And in these cases, the vaccine isn't terribly effective and we really have no protection," he said.