PROCESS FOR THE PRODUCTION OF FOOT-AND-MOUTH DISEASE VIRUSES ADAPTED TO TISSUE CULTURES.

摘要

. In a process for the production of an inactivated FMD-virus vaccine the step which consists of adapting foot-and-mouth disease viruses to tissue cultures, which comprises cultivating natural foot-and-mouth disease viruses in a tissue culture of organs of claw-foot animals using an inoculating quantity whose volume to cell surface ratio ranges from 1:1 to 1:50 and which has a virus titer of 10s to 1010 mice-LDS4( removing after 5 to 120 minutes the supernatant solution containing unadsorbed viruses adding a nuttieut solution suitable for virus propagation, harvesting the virus-containing supernatant after 12 to 48 hours and subjecting it to further passages with reduced inoculation quantities, or bringing the virus-containing supernatant of the first passage, in undiluted state and in decimal dilutions, onto tissue cultures of organs of claw-foot animals cultivated in glass containers having a fiat bottom, removing after 5 to 120 minutes the supernatant containing uuadsorbed viruses,  covering the cell monolayer with a nutrient solution contatning a viscosity-increasing substance and having a volume to cell surface ratio of 1:3 to 1:20, taking samples of the suspension after 18 to 72 hours from above a plaqae of the solution having the highest dilution degree but still containing plaques, and bringing the said samples onto a tissue culture, and then further cultivating and harvesting the viruses in known manner.