Although no cases of human-to-human transmission of the deadly H5N1 strain of bird flu have been reported, scientists fear the virus could mutate into a strain that could pass easily between people, causing a global pandemic.
The vaccine, developed by GlaxoSmithKline PLC and called Prepandrix, is a mix of antigens from currently circulating virus strains, and is aimed at offering protection against bird flu ahead of a major outbreak.
Tests of the vaccine have been conducted in 400 adults aged between 18 and 60 since the fall of 2006, and showed at least a four-fold increase in serum neutralizing antibodies in 77% to 85% of subjects against three distinct H5N1 strain variants.
The European Medicines Agency believes that Prepandrix "will provide a clinically useful degree of cross-protection against the strain that causes the next pandemic," EurActiv reported.
However, scientists maintain that the large-scale commercial production of a true pandemic vaccine is unlikely to start before the virus mutates into its pandemic strain.
According to the World Health Organization, avian influenza has so far killed 241 people out of 382 confirmed cases worldwide.
GlaxoSmithKline intends to donate 50 million doses of Prepandrix to the World Health Organization for distribution to the world's poorest countries.
