China has prepared the H7N9 vaccine seeds for mass production in case human-to-human transmission occurs, a deputy to the National People's Congress (NPC) said Monday.

China has manufactured some vaccine products and they could be used on high-risk groups, Zhong Nanshan, NPC deputy and member of the Chinese Academy of Engineering, said at a press conference at the annual parliamentary session.

Zhong, a pulmonologist, is the lead scientist who helped China battle SARS in 2003.

"China did a good job in 2009 when about 100 million people were vaccinated for the H1N1 virus," said Zhong, while stressing the effectiveness of vaccines when it comes to inter-human transmission.

In February, the Shanghai Public Health Clinical Center announced that they have developed a genetically engineered vaccine for the H7N9 bird flu virus and have now entered the clinical trial application phase.

H7N9 cases were reported in several places in China and it has a mortality rate of 30 percent, Zhong said, adding that if the virus transmutes, it could lead to a larger outbreak.

There has been no H7N9 inter-human transmission so far and cases are still mostly sporadic, Zhong said, adding that no accurate transmission route has been discovered.

However, from the view of epidemiology, over 80 percent of patients were infected at poultry markets, Zhong said, adding that unlike H5N1, the H7N9 virus only infects people, not poultry.

Live poultry trading has been halted in several provinces, especially where large numbers of human H7N9 cases were reported.

It makes more sense for people to slaughter all the poultry in the case of H5N1 as both human and the poultry are infected, said Zhong, adding that for H7N9, slaughtering all the poultry is less appropriate and would affect the food industry that involves millions of people.