It has been reported that a 'universal' flu vaccine could be the 'one fits all' jab, a new two-step approach to immunization.

The US team, working with mice, ferrets and monkeys, 'primed' the immune system with a 'base' of influenza DNA.

They added a 'booster' consisting of a regular seasonal flu vaccine, which increased and broadened its immunity.

Early safety trials of the vaccine have already started and it could be tested on patients as early as 2013, The Telegraph has reported.

Mice and ferrets were able to fight off the deadly strain of 1934, strains from 2006 and 2007 and H5N1 'bird flu'.

It was also reported that flu viruses are notorious for their ability to mutate and become resistant to vaccines.

Antibodies target a lollipop-shaped flu virus surface protein called haemagglutinin (HA). But the structure of the protein's "head" mutates readily, allowing the virus to go undetected when it changes form.

Professor John Oxford, Britain's leading flu expert and a virologist at St Bart's and Royal London hospitals, said, "This a new and interesting approach and they are a very respected group. I would take this very seriously. They seem to have identified a universal or general antibody that attacks many different types of virus." (With Inputs from Agencies)