HANGZHOU - Chinese researchers announced Saturday they had successfully developed the vaccine for the H7N9 bird flu virus, after the flu strain had left more than 130 people infected, with 45 fatalities reported.

Shu Yuelong, director of the Chinese National Influenza Center, said this is the first influenza vaccine ever developed by Chinese scientists.

The vaccine has provided important technical support to battle the new flu strain, making contribution to the H7N9 flu virus epidemic control all over the world, said Shu, also director of the WHO Collaborating Center for Reference and Research on Influenza.

The vaccine was jointly developed by the First Affiliated Hospital under the School of Medicine of the Zhejiang University, Hong Kong University, Chinese Center for Disease Control and Prevention, National Institute for Food and Drug Control, and the Chinese Academy of Medical Sciences.

Li Lanjuan, leading researcher from the Chinese Academy of Engineering, said the team started research after they successfully isolated H7N9 bird flu virus from the throat swab sample of an infected patient on April 3.

The team applied plasmid reverse genetics and genetic reassortment, which was widely adopted by the world, to develop the vaccine seeds, which were later proved to be safe with the embryonated chicken eggs, she said.

Currently, the vaccine has passed the test on ferrets, which was conducted by the Institute of Laboratory Animal Sciences of the Chinese Academy of Medical Sciences. Drug authorities have also verified the vaccine in accordance with relevant requirements of Chinese Pharmacopoeia.

At the news conference on the research findings held Saturday in Hangzhou, capital of east China's Zhejiang Province, medicine producers, such as Tianyuan Bio-Pharmaceutical Co., Ltd., showed interest in the vaccine's production, although the virus has not been spread widely enough for mass inoculation.

China reported the world's first human case for H7N9 bird flu infection in March. As of Friday, a total of 136 people were confirmed to have been infected with the virus, according to the National Health and Family Planning Commission (NHFPC). Of the infected, 45 died, representing a fatality rate of 33.1 percent. No cases have been reported so far in other countries.

Liu Dengfeng, deputy chief of the science and education department of the NHFPC, said, as the weather temperature went down, the epidemic would return, considering new cases had been reported lately.

On Oct. 15, and 23, two new H7N9 bird flu infection cases were reported in Zhejiang Province, the latest since the previous ones reported two months ago.