Abstract: The research and development of attenuated vaccine of porcine transmissible gastroenteritis virus (TGEV) was conducted by Harbin Veterinary Research Institute in 1978, when the swine industry was suffered a severe loss in China. The project financially supported by the National Technologies Research and Development Program during the National Sixth Five-Year Plan Period. TGEV virulence strain of H27 at 4th passage in fetal porcine kidney primary cell was treated with the medium containing DMSO and passed in the cell up to 165th passage. During the series cell passage, the plaque purifications were performed at 92nd passage for 5 times, and the virus strain was further purified by picking up the virus plaque less than 1mm in diameter at 116th passage, virus titer were 104.67-106.0TCID50/0.3ml from 100th passage. A high level of neutralization antibody was maintained and lasted for 13 months in sow immunized by intranasal route. The protection for 3-day-old piglets was 75.9%-94.3% by the vaccine inoculation, and over 97% of piglet was protected by taking colostrums containing the neutralization antibody. The vaccine was stabile by passing 5 passages and 6 passages through piglets with 120th and passage 135th passage, respectively. The immune persistent period of three pregnant sows inoculated with 5ml dose by intramuscular route and intranasal route lasted two products. The safety of the attenuated vaccine attested to several years’ trial in some large swine-raising farms, and could effectively against TGEV infection. The research of TGEV attenuated vaccine obtained the second prize of Science and Technology Progress Award of Ministry of Agriculture in 1986 and the third prize of National Science and Technology Progress Award in 1988, respectively.

Key words: Transmissible gastroenteritis virus , Attenuated vaccine