Vaccinia Virus and Human Blood-Group-A Substance

Abstract

A material similar in antigenic properties to human blood-group A substance was demonstrated in normal embryonated egg membranes and egg "fluid". It is thought therefore that claims to have demonstrated an A-like substance in vaccinia virus are probably due to the presence of egg materials in the virus preparations used. In the sera of rabbits immunized within vaccinia virus prepared from infected rabbits there was no increase in the titer of anti-A. Absorption of these and other antivaccinial sera with human blood-group A1 cells did not reduce the titer of virus neutralizing antibodies. A high-titer rabbit anti-A has no effect on the growth of the "Lister" strain of vaccinia virus on chick chorioallantois. This finding renders doubtful any direct connection between the occurrence in humans of anti-A and resistance to vaccination and to smallpox. The effect of a purified preparation of human blood-group A substance on the growth of the Lister strain of vaccinia virus on chick chorioallantois did not differ materially from that observed with a purified preparation of human blood-group-B substance. This suggests that it is unlikely that response to vaccination or possibly susceptibility to smallpox would be related in a simple specific way, if at all, to the incidence of blood-group A in human populations.