For example, Tamiflu is effective only if taken within 48 hours after 
contracting the virus. 
The fatality rate for human infections is about half and patients usually die 
within a week of being infected. 
Amantadine and rimantadine are also used in China against human infections. 
While neither is recommended any longer by the World Health Organization as 
the virus has developed resistance in some countries, "they are still effective 
in China," said Chen Hualan, the country's top veterinarian from the Harbin 
Veterinary Research Institute, the only one involved in bird flu research. 
In the past week, China has announced several breakthroughs in the battle 
against bird flu. 
On Saturday, scientists at Chen's laboratory announced the development of the 
world's first live vaccine against bird flu and Newcastle disease, two killer 
infections for poultry. 
Last week, clinical trials began for a human vaccine against H5N1 and 
Beijing-based Sinovac Biotech Co Ltd, which developed the vaccine, said the 
exercise may last a year. 
Yin Weidong, managing director of Sinovac, said China would need 200 million 
doses of the vaccine. 
"It is better to build up the production capacity of seasonal vaccines, so 
that when a pandemic occurs, companies can quickly start mass production," said 
Yin. 
The country has reported six human infections of bird flu of which two died 
by yesterday and 31 major outbreaks among poultry. 
The disease has cost the domestic poultry industry losses of more than 60 
billion yuan (US$7.5 billion) between October and December, according to 
official figures. 
But thanks to China's aggressive preventive measures, 30 out of 31 outbreak 
sites have been lifted out of epidemic isolation. By December 14, China had not 
reported a new case within half a month.