New Study Shows GSK’s Candidate Vaccine Provides Asians Immunity Against Bird Flu Strain

GlaxoSmithKline (GSK) announced that data from its Asian H5N1 vaccine clinical trial demonstrated that its candidate pre-pandemic H5N1 vaccine elicited a favorable immune response against a variant or “drifted” strain of H5N1 and demonstrated a positive safety profile in an Asian population. These results are particularly significant in Asia, where 75% of human deaths due to H5N1 infections have been reported and where an increasing number of infections continue to be seen.

GSK’s clinical study was conducted in 4 Asian countries, namely Hong Kong, Singapore, Taiwan and Thailand involving 1,206 persons, aged 18-60 years. Participants were administered with two doses of GSK’s candidate pre-pandemic vaccine given 21 days apart. Blood tests conducted three weeks after the second dose was given showed high levels of neutralizing antibodies against the Vietnam and Indonesia H5N1 strains (96% and 91.4% respectively).

An influenza pandemic could have a devastating effect on the world as it involves viruses to which humans have little or no immunity. However, the exact strain that may cause an influenza pandemic cannot be accurately predicted. Therefore, the pre-pandemic vaccine is currently based on the H5N1 strain as experts believe this to be the most likely candidate pandemic strain.

The Asian study supports recent findings from a European study showing that GSK's candidate pre-pandemic vaccine also promotes immunity against the Anhui (China) and Turkey H5N1 strains. Furthermore, antibodies against these strains were still detected 6 months after vaccination, representing persistence of immunity. These results demonstrate how the candidate vaccine offers the possibility of protecting populations against an eventual pandemic strain.

In recognition of pre-pandemic vaccination as an important strategy for addressing the current pandemic threat, GSK’s candidate pre-pandemic vaccine received a Positive Opinion from the Europe’s Committee for Medicinal Products for Human Use (CHMP) in February 2008. This is the first candidate pre-pandemic influenza vaccine to receive a Positive Opinion from the CHMP.7

Although there has not yet been any sustained human-to-human transmission of H5N1, it is generally accepted that it is only a matter of time before the world is confronted with another pandemic outbreak of influenza which will lead to morbidity and mortality worldwide. The World Health Organization has advocated for countries to develop pandemic preparedness plans to mitigate the effects of future influenza pandemic.

"A pandemic clock is ticking and we don’t know what time it is,” says Prof. Dr. Albert Osterhaus, a virologist from the Erasmus Medical Centre in the Netherlands. “The availability of a safe and effective pandemic influenza vaccine that can be used to vaccinate the world population preventively would be the most effective and cost-effective way to combat such a disaster."

As one of the world’s leading research-based pharmaceutical and healthcare companies GSK is committed to improving the quality of human life by enabling people to do more, feel better and live longer.