摘要 |
<p>In the production of transmissible gastro-enteritis (T.G.E.) virus vaccine, virulent particles of the virus are inoculated into a first tissue culture, the virus is incubated therein for a period up to 24 hours, preferably for from 6 to 14 hours, the viral particles are removed from the culture and inoculated into one or more further tissue cultures, and the incubation and inoculation into further tissue culture or cultures is repeated one or more times. The virus is obtained from the mucosa of the intestinal tracts of infected pigs. Tissues of swine, sheep, cattle, dogs, ferrets and cats may be employed; however, it is preferred to use dog kidney cells for each tissue culture. The incubation of the virulent virus is carried out at 35 DEG to 38 DEG C. The propagation of the virus may be continued until it is rendered avirulent. An inactivated vaccine may be prepared by combining a virus-containing culture with a stabilizing menstrum and incubating at 25 DEG C. for five days. The vaccine can be stored at a low temperature or freeze-dried. Sows and their nursing pigs can be immunized against transmissible gastro-enteritis virus by injecting the virus vaccine into the pregnant sow six weeks before farrowing, thereby stimulating the production of anti-bodies which protect the sow, and nursing the pigs on the sow thereby protecting them against the virus by way of anti-bodies passed in the milk.ALSO:In the production of transmissible gastroenteritis (T.G.E.) virus vaccine, virulent particles of the virus are inoculated into a first tissue culture, the virus is incubated therein for a period up to 24 hours, preferably for from 6 to 14 hours, the viral particles are removed from the culture and inoculated into one or more further tissue cultures, and the incubation and inoculation into further tissue culture or cultures is repeated one or more times. The virus is obtained from the mucosa of the p intestinal tracts of infected pigs. Tissues of swine, sheep, cattle, dogs, ferrets and cats may be employed; however, it is preferred to use dog kidney cells for each tissue culture. The incubation of the virulent virus is carried out at 35 DEG to 38 DEG C. The propagation of the virus may be continued until it is rendered avirulent. An inactivated vaccine may be prepared by combining a virus-containing culture with a stabilizing menstrum and incubating at 25 DEG C for five days. The vaccine can be stored at a low temperature or freeze-dried. Sows and their nursing pigs can be immunized against transmissible gastroenteritis virus by injecting the virus vaccine into the pregnant sow six weeks before farrowing, thereby stimulating the production of antibodies which protect the sow, and nursing the pigs on the sow thereby protecting them against the virus by way of antibodies passed in the milk.</p> |