Chinese scientists come up with safe and effective bird flu vaccine

Aug 29 2006

According to official reports a bird flu vaccine for humans developed by Chinese researchers has proven to be both safe and effective.

The vaccine which was a joint enterprise between China's Ministry of Science and Technology, Center for Disease Control and Prevention and the pharmaceutical company Beijing Sinovac Biotech, proved itself worthy in the first phase of clinical trials of the vaccine on six volunteers.

The trials were started last November at the Beijing China-Japan Friendship Hospital, following approval from the State Food and Drug Administration.

The researchers say that results from the trials, which ended in June, showed that the four antigens worked at different levels in stimulating the production of antibodies, and a 10 microgram dosage of the vaccine proved most effective, and appeared to provide 78.3 percent protective antibodies, which exceeds the European Union standard of 70 percent for a flu vaccine.

The researchers say all the participants who were vaccinated have shown no serious adverse reactions, and blood and urine tests indicate that the vaccine is safe for human use.

The World Health Organization (WHO) provided a sample of the virus's NIBRG-14 strain from which the vaccine was developed.

This particular strain protects against the deadly H5N1 strain of avian influenza and according to the researchers the vaccine is capable of being mass produced.

Work on the vaccine began last year, and the government says it is ready to start mass production as soon as more tests are completed.

The vaccine is apparently meant initially for high-risk groups such as poultry workers.

Beijing Sinovac Biotech says it is ready to apply for the second phase of clinical trials, as Chinese health regulations demand a vaccine is only allowed on the market following three successful phases of clinical trials.

Although bird flu remains essentially an animal disease, which is only contracted by some form of exposure to infected birds, experts continue to worry that any mutation of the H5N1 virus could enable it to pass easily among humans triggering a pandemic.

Across the world a number of companies are currently conducting clinical trials on bird flu vaccines but the unpredictability of the H5N1 virus means drug companies take a gamble in developing a vaccine as there is no way of knowing which virus is most likely to mutate into a killer strain.

The U.S. National Institute of Allergy and Infectious Diseases is also conducting trials on an H5N1 vaccine for humans.

To date the virus has killed 14 people in China since 2003 and 21 Chinese have contracted the virus.

The latest case was a 62-year-old man in Xinjiang Uygur Autonomous region, who died on July 12.

Word wide 141 people have died and millions of birds have either been directly killed by the virus or culled because of it.