A trial of the latest bird flu vaccine has shown it may be more effective in protecting Asians than Caucasians, published results said on Monday.
The vaccine by GlaxoSmithKline gives good protection against the four strains of the disease that have infected humans in Vietnam, China, Indonesia and Turkey, the findings said.
Most of the victims of bird flu have been Asians, said Professor Praser Thongcharoen of Thailand's Medicine Siriraj Hospital.
The Asian trial involved more than 1,200 people in Thailand, Taiwan, Hong Kong and Singapore, and the vaccine was still effective six months after it was given, The Straits Times newspaper said.
Trials are continuing to determine how long the immunity lasts, Thongcharoen said.
The vaccine is expected to receive European approval by next month.
Since 2003, 366 people have been infected by the virus through contact with infected poultry; 232 of them have died.
The World Health Organisation has encouraged countries to take precautions in case of a pandemic that could spread quickly among nations.
"If a pandemic breaks out in Indonesia or Thailand, the virus could be in Singapore within two days," Dr Helen Oh, in charge of the Singapore trials, was quoted as saying.