The UK Government has said it plans to lay in enough supplies of pandemic flu vaccine to provide two doses for each member of the population, once the identity of the strain has been established.

Two doses are required to achieve protective immunity because people have never been exposed to a flu virus similar enough to impart even partial immunological protection.

The UK’s Chief Medical Officer, Liam Donaldson, said yesterday that manufacturers are being invited to tender contracts to supply 120 million doses of pandemic flu vaccine, placing the UK at the forefront of countries around the world in its defence strategy against the virus.

However, there will still be a delay of several months after the strain is identified to allow the vaccine to be manufactured, and the issue of manufacturing capacity is a major one. One industry source has estimated that, at present, worldwide production capacity of the world for producing an avian flu vaccine using traditional methods is less than 40 million doses, and would cost several hundred million dollars to make.

Other are somewhat more optimistic, including Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, who suggested this week that if all flu vaccine capacity was turned over to pandemic flu vaccine production, 450 million doses could be made within six months. But that is still only enough to protect less than 10% of the world’s population.

This shortfall suggests other forms of control – such as the isolation of patients, contact tracing, mass quarantine and bans on international travel – will be at least as important in combating the spread of the disease.

Donaldson told a press conference that the UK Government wants to set up ‘sleeping’ contracts as an incentive for companies to start laying down production capacity for pandemic flu vaccines.

The UK’s move comes as the H5N1 strain of avian influenza – considered the most likely candidate to cause a flu pandemic at present – has arrived at the edges of the European Union, with cases affecting poultry in Greece, Romania, Turkey and now Russia. Sixty people around the world have already died after contracting avian influenza from birds. If the virus mutates sufficiently to allow human-to-human transmission, the resulting pandemic could cause millions of deaths around the globe, according to the World Health Organisation.

Last month, the UK Government also placed an order for 14.6 million doses of Roche’s influenza drug Tamiflu (oseltamivir) at a cost of £200 million. This stockpile is due to be in place by September 2006.

- Meanwhile, Canadian company Generex Biotechnology joined the ranks of those developing influenza vaccine strains yesterday, announcing that its wholly owned subsidiary Antigen Express has started making H5 hybrid vaccine peptides that could form the basis of a vaccine.