The UK government has bought more than 5 million doses of bird flu vaccine to fight a potential pandemic as cases among animals increase.
The move comes amid an increase in the spread of the virus among birds, according to the UK Health Security Agency.
However, the jab is only intended for use if the virus were to spread among humans and there is currently no evidence of human-to-human transmission.
Sir Andrew Pollard, director of the Oxford Vaccine Group, University of Oxford, said: “Emergence of a new strain of influenza remains at the top of the list of pandemic threats and so providing resilience against potential risky flu types, like H5, is important for future pandemic and outbreak preparedness.
“H5 is only one of the multiple families of flu viruses that create such a risk, so we should not be complacent. But H5 is the one that we are most concerned about today as a result of the global spread of this virus amongst birds and various mammals, and worryingly across the United States amongst cattle this year. H5 is out there and we need to do all we can to be prepared.”
Dr Meera Chand, Emerging Infection Lead at the UK Health Security Agency, said: “It is important for us to be prepared against a range of different influenza viruses that may pose human health risks. Early access to vaccines saves lives. Adding H5 vaccines to the interventions already available to us will help us to be ready for a wider range of threats.”
Recent cases of bird flu were identified at a farm in Yorkshire, while 57 cases in humans have been reported in the US.
Professor Ian Brown, group leader for The Pirbright Institute, said the spread of the flu across birds and animals was at such a scale that the risk to humans has increased.
He added: “There are occasional spillover events to humans, principally to those who have been occupationally exposed to infected birds and animals, with most human infections being mild.
“The H5 viruses presently lack the properties to efficiently infect the upper respiratory tract of humans and transmit between. However, a vaccine stockpile is an important preparedness step should H5 viruses mutate and expand their capability to infect and transmit between humans. If this scenario were to occur vaccine stockpiles would have an important role in the early control of substantially increased risk or a pandemic.”