Abstract
Comparative analysis of antigens of vaccinia, ectromelia, fowl pox, pigeon pox and canary pox viruses were made by various precedures of complement fixation test with the following results:
(1) The mammalian pox viruses, vaccinia and ectromelia, demonstrated so strong cross reaction that the differentiation of these viruses was difficult by this reaction.
(2) The viruses of fowl pox, pigeon pox and canary pox were found to be closely related in the antigenic make-up. The extent of cross reaction indicated that fowl pox and canary pox viruses were relatively different and the pigeon pox virus was between them.
(3) No antigenic relationship was revealed between the group of mammalian viruses and that of avian viruses.
Based on these findings, the classification of these two groups of viruses was discussed.
