Modulation of humoral immune response to influenza vaccines by BCG

BCG-induced modulation of humoral immune response to influenza vaccines was studied on adult volunteers and laboratory animals. Three influenza vaccine types were used: inactivated whole-virion vaccine prepared by chromatography, chemically split adsorbed vaccine and live allantoic vaccine for intranasal vaccination. According to the indices of humoral immunity against influenza such as seroconversion, frequency and intensity of antibody formation and degree of protection to subsequent administration of the vaccine virus, the BCG vaccine had a marked immunomodulating effect in combination with the adsorbed chemically split vaccine. The effect was slight in the case of the whole-virion vaccine and was absent with the live attenuated vaccine.