China approves bird flu vaccine for humans

By Tan Ee Lyn

HONG KONG (Reuters) - Beijing has given the go-ahead to a Chinese drug maker to begin large-scale production of a human bird flu vaccine, after a second clinical trial showed the vaccine was safe and effective, the company said on Thursday.

The vaccine uses an inactivated whole H5N1 virus from Vietnam, said an official for Sinovac Biotech, which jointly developed the vaccine with China's Centers for Disease Control.

"We finished our second trial in November. We checked our 402 participants for antibodies and they met international standards used in the United States and the European Union both for safety and immune response," Sinovac's publicity supervisor Liu Peicheng told Reuters by telephone.

China's State Food and Drug Administration said on Wednesday it had authorized production of the vaccine.

The vaccine was used in amounts of 5, 10 and 15 micrograms but the 10 microgram dose was found to be ideal.

"The 10 and 15 microgram doses met standards but we decided on 10 as it's good enough. It would use less antigen," said Liu.

Antigens are substances like toxins, viruses and bacteria that stimulate the production of antibodies when introduced into the body. But they can be difficult to culture and scientists have been trying to fix that by using boosters, or adjuvants.

Participants in the Chinese trial were between the ages of 18 and 60. Liu said only some minor side effects were recorded, in line with those sometimes seen with seasonal flu vaccines. He did not elaborate.