Brits to trial bird flu vaccine on humans

Jul 10 2006

The British drug company PowderMed has applied for permission to conduct the first trial in Britain of a vaccine against the avian flu virus.

The company which is based in Oxford, has asked the Medicines and Healthcare products Regulatory Agency (MHRA) for clearance to test its H5N1 vaccine on 75 volunteers at Guy's Hospital in London.

The lethal H5N1 strain of avian flu has spread rapidly throughout bird populations in Asia and into Europe by flocks of migrating waterfowl.

To date the World Health Organisation has reported 97 human cases of avian flu since December 2003, with at least 53 deaths and the long standing fear has been that the lethal H5N1 strain of the virus might mutate into a form easily transmissible between humans, potentially triggering a worldwide pandemic.

The MHRA is expected to grant approval for the trial to proceed.

Any effective vaccine against avian flu would considerably augment efforts to limit the infection's spread if a pandemic strain emerges, by supplementing the government stockpiles of the anti-viral drugs Tamiflu and Relenza.

The proposed vaccine differs from conventional vaccines in that it is based on weakened strains or fragments of the virus and can be produced quickly and cheaply.

Volunteers in the trial will be subjected to an alternative to the needle jab and will get instead a handheld device which will blast harmless, microscopic gold particles coated in the vaccine into the upper arm at supersonic speeds.

Tests earlier this year of a DNA vaccine designed to give protection against seasonal flu showed that it offered 100% protection, based on the immune response of volunteers.

The DNA vaccine against avian flu as yet has only been tested in animals, where it has also proved successful.

John Beadle, the chief medical officer at PowderMed, said that it would be possible to create a new vaccine in about ten weeks, much more quickly than traditional vaccines, which are developed in hens' eggs.

Research suggests two doses of the vaccine, a prime and a booster will be needed to give adequate protection.

Details of the trial can be found on the U.S. Government's website, Clinicaltrials.gov where it states it is seeking 75 volunteers for the trial at Guy's drug research unit in London.

The company plans to test the volunteers over several months to monitor how long the vaccine remains effective and preliminary results are expected in January next year.