Sex differences in B cell frequencies and antibody responses following influenza vaccination in healthcare workers during the 2019–2020 season

Abstract

Abstract Annual influenza vaccination for healthcare workers (HCWs) is required at Johns Hopkins to reduce influenza spread in healthcare facilities. We conducted a clinical study to evaluate sex differences in virus-specific antibody-producing B cells (i.e., plasmablasts) following receipt of the seasonal influenza vaccine in a highly vaccinated population of healthcare workers. To understand sex differences in immune responses to the influenza vaccine in the HCWs, 83 participants consented to blood draws at baseline and 75 participants returned for the 7- and 28-days post-vaccination survey and blood draw. Participants received their annual quadrivalent influenza vaccine (QIV). Influenza A specific plasmablasts were quantified at baseline and day 7 post-vaccination. Males had a significantly greater percentage of influenza-specific plasmablasts than females after vaccination (p<0.0003) Plasma collected at baseline and at day 28 post-vaccination was used to measure neutralizing antibody (nAb) titers against H1N1 and H3N2 vaccine viruses. Neutralizing antibody responses against either the H1N1 and H3N2 viruses increase after vaccination to the same degree in both males and females. The proportion of plasmablasts at day 7 was significantly associated with the vaccine-induced fold rise in nAb. This relationship differed by sex, whereby for a given proportion of plasmablasts, females tended to mount a greater fold-rise in nAb than males. These data suggest that despite having potentially fewer plasmablasts after vaccination, females mount an antiviral antibody response to the influenza vaccine viruses equivalent to males. Identification of transcriptional differences in plasmablasts from male and female HCWs is ongoing.