Scientists take a step closer to a universal flu vaccine

Two separate US teams had reported success with an approach that homed in on a stable part of the flu virus, in the fight against influenza.

That would eliminate the problem with current flu vaccines when needed to be given anew each year as they focused on the mutating part of the virus.

Science journal and Nature Medicine have published the proof-of-concept work. Studies would now be needed to be undertaken in humans to confirm that the method would work in humans.

In the meantime, according to experts, people would do well to have an annual flu jab because vaccination continued to be the best way to protect against infection.

Flu is especially contagious and spreads from coughs and sneezes of an affected person.

Influenza viruses are covered in lollipop-shaped proteins called hemagglutinin, which they use for entering cells.

The immune system produces molecules called antibodies that bind to neutralise the head of HA.

But HA mutated over and over again thus escaping detection. The HA head varied widely across different flu viruses, but HA's stem tended to stay the same.

In 2008, scientists discovered unusual antibodies in humans that could bind to the stem of HA in many different flu strains. This was what researchers had been looking for.

Ian Wilson, a virologist at the Scripps Research Institute who co-authored the second study with colleagues at the Crucell Vaccine Institute, now known as the Janssen Prevention Center, said with this, it was possible to protect not only against seasonal flu from year to year but also perhaps against other influenza viruses like bird flu or new strains emerging in the human population.

A four-year study of 1,414 unvaccinated people across England found that 43 per cent of them had immune cells that protected them from symptoms of both seasonal and pandemic influenza, and reduced their chances of shedding the virus by two thirds. (See: 'Core' immune cells reduce symptoms and spread of flu)