A security guard wearing respirator stands on duty at Donghu Hospital in Shenzhen, Guangdong province June 13, 2006. The suspected bird flu patient is undergoing treatment at the hospital. [newsphoto]

The vaccines, if used together, "offer a solid technical guarantee for the Chinese government to effectively control highly pathogenic avian influenza," the ministry said, referring to the deadly strain of H5N1 bird flu.

The vaccines were developed by the National Avian Influenza Reference Laboratory.

Lab director Chen Hualan said the vaccines have not yet been put into full production, but they have already proven effective in preventing and controlling the spread of avian influenza.

State authorities are also expanding their attention to scientific research into avian flu vaccines. Nine companies have been appointed by the Ministry of Agriculture to produce vaccines.

A new diagnostic test for detecting the H5 virus can single out H5 subtypes in a little over 10 minutes, an advance that's highly important for rapid control of a bird flu epidemic, the ministry said.

China has reported 18 human infections of bird flu since last November, including 12 fatalities. The last case was confirmed on April 27.

On Tuesday, a 19th possible case was reported in Shenzhen in southern China's Guangdong Province. Preliminary tests show that a 31-year-old man surnamed Jiang had contracted the H5N1 virus. District health officials yesterday were still awaiting confirmation from state authorities.

Globally, 225 human infections, including 128 deaths, have been recorded by the World Health Organization.

China's central government is strengthening its prevention and control of bird flu, a health official said on Monday.

The Ministry of Agriculture has issued an emergency order for local governments to tighten controls over poultry stocks to prevent the spread of avian flu from migratory birds.

The ministry also started a national check this week on the implementation of its immunization policy across many areas of the country. Some 31 inspection groups were dispatched to farm regions to check the effects of the immunization program.

The campaign was organized by the China Animal Disease Control Center, a new department under the Ministry of Agriculture.