[In vitro proliferative activity of lymphocytes from elderly persons after separate and combined immunization with...

Cellular (lymphocyte proliferation activity--LPA), humoral (serum antibodies), and secretory (IgA antibodies from the upper respiratory tract) immune responses were compared in 45 subjects aged 66-95 years, vaccinated with two influenza trivalent A(H1N1) + A(H3N2) + B vaccines: Russian live attenuated cold-adapted reassortant (LIV) and USA inactivated split-virus (IIV) vaccines. None of immunization protocols suppressed LPA after in vitro stimulation of cell culture with homologous virus antigens and nonspecific polyclonal mitogen (PHA). Simultaneous LIV + IIV vaccination was the most effective method of immunization, inducing humoral, secretory, and cellular immunity. LIV more actively than IIV stimulated the lymphoproliferative immune responses. Fluctuations in the mean values of cellular, humoral, and secretory immunity were in good correlation over the entire period of observation (19 weeks). Analysis of individual immune responses showed that a significant increase in quantitative parameters of LPA was observed only in 39-52% vaccinees.