[Cytogenetic characteristics of the vaccination process in children, primarily vaccinated against smallpox]

An increased rate of chromosome aberrations in the peripheral blood lymphocytes was observed in children between 1 and 21/2 years of age beginning at 4 days after vaccination. The number of aneuploid cells and chromosome aberrations increased for 1 month but were not found 6 months after vaccination. Administration of measles gamma-globulin in a dose of 0.75 ml before vaccination did not influence significantly the frequency of chromosome aberrations. A direct correlation was observed between the height of the immune response and the rate of chromosome aberrations. The observed changes in the chromosomal apparatus are not specific for the effect of vaccinia virus but indicate sterotypic reaction of the macroorganism in response to an alien antigen.