Immunological reactions after measles vaccination

Evaluation of immunological reactions after vaccination with attenuated measles virus wasbased on determination of the level of hemagglutination-inhibition (HI) and neutralizing (N) antibodies, their location in basic groups of immunoglobulins, and the degree of blastic transformation induced by phaseolin. The picture of lymphocyte chromosomes of the peripheral blood was also investigated. HI and N antibodies were detected not earlier than on the 14th day after vaccination, reaching a peak on the 30th day. Sera were fractioned on Sephadex G-200 gel or centrifuged in sucrose-density gradient. On the 14th day activity of antibodies was located mainly in IgM fractions, and in a later period mainly in IgG and partly in IgA and IgM. Decrease in blastic transformation was found on the 7th day after vaccination, when HI and N antibodies were not detectable. Further decrease in transformation was observed on the 14th day after vaccination. Mitotic indexes increase significantly only on the 30th day after vaccination. For the whole period of observation there were no changes in the number and structure of chromosomes.