GlaxoSmithKline Plc plans to seek European approval in October for a new vaccine to prevent bird flu in humans, the head of its vaccines business said on Thursday.

Europe´s biggest drugmaker, which started clinical trials of two experimental vaccines in March, has previously said it expected a protective shot would be ready for manufacture by the end of the year.

"We will apply for regulatory approval of a vaccine in October 2006," Jean Stephenne told reporters at a briefing.

Glaxo hopes to have the clinical data necessary to assess the effectiveness of its vaccines by August and September, he added. It also intends to present the results of its clinical studies to a scientific conference in October.

Several drugmakers are working to develop vaccines against the H5N1 strain of bird flu, but Glaxo believes it may have an advantage because it is using special adjuvants -- additives put into vaccines that boost the immune system.

Scientists believe vaccines from Glaxo and rivals such as Sanofi-Aventis might protect people from "drifted" strains of H5N1 -- those that have evolved slightly and do not precisely match the strain of virus used in the vaccine.

That could make them a good option for governments building up stockpiles.

The H5N1 strain of avian influenza has spread rapidly out of eastern Asia in recent months. It almost exclusively infects birds but has killed 130 people since 2003, mostly in Asia.

Experts believe it poses the greatest threat yet of a pandemic, a global epidemic of flu that could kill millions, if it acquires the ability to pass easily from human to human.

No one knows how well human H5N1 vaccines will match a future pandemic strain, but they might prime a person´s immune system, reducing sickness and death.

The normal seasonal flu vaccine provides no protection against H5N1.