Response of camels to intradermal inoculation with smallpox and camelpox viruses.

Young camels were inoculated intradermally with either camelpox or smallpox virus and the courses of infection, including serological response, were compared. Camelpox virus was highly infectious; generalized disease resulted which was transmitted naturally to contact animals. Smallpox virus produced only transient lesions at the inoculation site and a less marked serological response. Nevertheless, the camels inoculated with smallpox virus subsequently resisted a severe challenge with camelpox virus, and the possibility that limited replication of smallpox virus took place is discussed. The differences demonstrated between the behavior of the vituses is discussed in the light of their otherwise close relationship and the limited information available about camelpox infections in man.