[Moscow Research Institute of Viral Preparations tissue-culture smallpox vaccine in a coded control experiments of adult revaccination by scarification]

Abstract

Comparative studies of tissue culture and dermal smallpox vaccines were carried out in a strictly controlled coded trial by revaccination of adults by scarification. Two lots of tissue culture and one lot of dermal vaccines with a similar infectious titer (8.0 lg PFU/ml) were used. All the lots tested "took" in 100%. In the group revaccinated with tissue culture vaccine seroconversion was observed in 94.2 +/- 2.8%--95.0 +/- 2.8%, with a 4.6 +/- 5.3-fold rise in geometric mean antibody titer; the dermal smallpox vaccine produced seroconversion in 85.7 +/- 4.4% with 4.3-fold rise in geometric mean antibody titer. Febrile reactions in revaccines with the tissue culture vaccine were observed in 23.1%--26.1% which did not exceed this parameter in the group revaccinated with the dermal vaccine (25.2%); in all the groups febrile ractions were of mild degree (37.1 degrees--38 degrees C). Local reactions of the type of confluent erythema were observed 1.8--5.3-fold more frequently among those revaccinated with the dermal vaccine than among those revaccinated with the tissue culture vaccine. Thus, the tissue culture vaccine used epicutaneously was as good as the dermal one by the take rate and antigenic activity, but had less remarked reactogenic properties which allows to recommend it for public health practice.