The world would quickly run out of flu vaccine in the event of a global pandemic despite efforts to improve production capacity, experts have warned.

Speaking at the launch of the World Health Organization’s new global influenza strategy Martin Friede, co-ordinator of immunisation, vaccines and biologicals at the WHO said that although the world is in better shape to combat a flu pandemic than ever before it is still "not prepared enough".

Better tools to prevent, detect, control and treat both pandemic and seasonal influenza are urgently needed, said the WHO. More effective vaccines and antivirals, particularly for low and middle income countries, are top of the list, the organisation added.

Dr Friede said that since 2006 global production capacity for vaccines had increased four fold, going from 1.5 billion doses to six billion.

“But that’s still not enough to go around the world as it’s probable that everyone would need two doses of the vaccine,” he said.

But he warned that it still takes too long to produce a vaccine. Currently, researchers have to wait to identify the particular strain of virus that is circulating and then formulate the vaccine - a process that takes about six months.