[Frequency of acrocentric chromosomal associations in children immunized with smallpox vaccine].

The frequency of associations of acrocentric chromosomes (AAC) diminished on the 7th day after vaccination in children primary vaccinated, primary revaccinated and secondary revaccinated against smallpox. This decrease reached its maximum by the 30th day and returned to its starting point after 6th months after vaccination. The degree of reduction of the frequency of AAC in every immunized children group correlated with the degree of increasing of antihemagglutinin titre. The relation of the number of group D chromosomes involved in AAC to the number of group G chromosomes varied in various individuals, these variations remaining after immunization. It was supposed that in PHA-stimulated lymphocyte cultures the degree of reduction of AAC frequency after vaccination against smallpox is a cytochemical marker of proliferation intensity of T-lymphocytes induced for immunopoiesis.