Cultivation of vaccinia virus in sheep kidney cell cultures.

Attempts to find a suitable tissue for the preparation of cell monolayers for the cultivation of vaccinia virus and for the titration of this virus and its antibodies resulted in the use of sheep kidneys procured from freshly slaughtered healthy young sheep. The cultures are easy and economical to prepare and support the multiplication of the virus well. They can be used for the titration of the virus and its antibody and their sensitivity to virus is comparable to that of the chorio-allantoic membranes of chicken embryos. Preliminary trials indicate that the sheep kidney cell culture virus can be freeze-dried without suffering a significant loss in titre. Studies are in progress to determine the efficacy of a vaccine prepared from sheep kidney cell cultures.