Deadly bird flu could spread worldwide because China is refusing to share samples of the virus
A Chinese strain of bird flu could cause a deadly global pandemic if it spreads because the country is slowing efforts to make vaccines, experts warn.
Both the UK and US governments have been denied samples of the H7N9 virus which they need to make a jab to protect people from the disease.
China could be breaking World Health Organisation rules by keeping its lab samples secret.
Experts say the virus, which is carried by poultry, could cause a worldwide pandemic and has so far killed more than a third of people who have been infected.
The latest figures from June revealed there have been 1,625 cases in humans since 2013 and 623 of those people died – a fatality rate of around 38 per cent.
Chinese authorities shared samples of the virus in 2013 and 2016 but scientists fear it could have evolved since then, making their earlier work out of date.
H7N9, a strain of avian flu discovered in 2013, is not yet thought to be able to spread between people.
But if it mutates to be able to do so experts predict it could sweep round the world.
This could cause a global health crisis because the disease has so far killed 38 per cent of people who have caught it.