The influence of influenza vaccinations on human peripheral blood lymphocytes relating to aging

Twenty healthy, aged more than 60 years were compared to 20 healthy young volunteers less than 40 years following influenza vaccinations. 0.5 ml, 10 U. of killed influenza vaccine Hong Kong B/873 was repeatedly given intramuscularly. Blood was collected before the vaccination, 6 days, respectively 6 weeks after vaccinations. The purified venous blood lymphocytes were examined by immunohistological and sheep erythrocyte rosette-forming methods. The absolute number of T and B lymphocyes was counted. It has been found that increase of IgG-bearing cells was higher in young persons, than in the elderly both in the first and in the revaccination. The absolute number of IgM-bearing lymphocytes increased in the aged after influenza vaccinations. The vaccine had no significant effect on the absolute number of IgA-bearing lymphocytes. The absolute number of T lymphocytes participating in the immune reaction showed a transitory increase solely in young persons. Experiments aiming to demonstrate the reduced activation of B lymphocytes in the elderly with the influenza vaccinations. It can be concluded, that the proliferation ability of the immunoglobulin-bearing B cells and T cells is reduced due to old age.