China is likely to receive samples of a flu strain by early June that will enable it to manufacture A/H1N1 influenza vaccine for human use by July, an official said Tuesday.

"The country has set up a green channel between the World Health Organization (WHO) and the Chinese drug makers. As soon as the WHO releases the vaccine strain, drug companies will be informed and will start manufacturing as soon as they can," Yin Hongzhang, head of the biology production department under the State Food and Drug Administration (SFDA), told Xinhua in an exclusive interview.

"If we can get the strain before early June, our drug companies will have produced the vaccine by July, under current conditions," Yin said. He said the green channel would save drug companies up to one month, compared with normal procedures for developing vaccines.

According to Yin, as vaccine manufacturing requires high-level safety, China must produce one in line with WHO protocols.

Last week, WHO said that drug companies wouldn't be able to make an A/H1N1 vaccine until mid-July at the earliest as the virus was growing slowly in labs, making it difficult for scientists to get the key ingredient for a vaccine.

Yin noted that WHO was not sure yet whether the A/H1N1 flu should be categorized as seasonal or pandemic, which was a problem for drug makers.

Seasonal flu occurs annually in predictable patterns, allowing people to develop resistance, while pandemic flu is rare, meaning that it's hard for people to develop resistance. In the latter case, vaccine doses need to be higher to be effective.

According to Yin, China has 11 drug companies that can produce seasonal flu vaccines but only one can make pandemic flu vaccines.

"Compared with a 1.3-billion population, our current vaccine producing ability is far from enough," said Yin.

He added that if the A/H1N1 influenza was confirmed as pandemic, the country would first guarantee vaccine supplies for medical staff.

Yin said a vaccine for A/H1N1 would produce antibodies within two weeks after being injected. It would take another 45 days to two months to take full effect, which would normally last for more than one year.

As of Tuesday, the Chinese mainland had 12 confirmed A/H1N1 flu cases.

Editor: Yan