HKU team hail H7N9 flu vaccine 'breakthrough'

University of Hong Kong researchers have developed a vaccine that may be the first in the world to offer a shield against many influenza viruses - including the deadly H7N9 bird flu strain - in one simple shot.

The HKU team described it as a breakthrough for seasonal flu vaccines, which can usually only provide protection against one or a few specific viral subtypes each.

The study found the new vaccine helped 80 to 100 per cent of mice fight different strains of flu viruses.

"Current influenza vaccines target only specific and individual subtypes, but it is difficult for scientists to predict which types of a virus will cause the next pandemic," the lead researcher, associate professor of public health Dr Leo Poon Lit-man, told the South China Morning Post.

"That is the reason why we should study whether there is another way to offer a broader spectrum of protection against different subtypes of viruses."

But it might take years before the vaccine is tested in human clinical trials, Poon said.