To evaluate the impact of prior SARS CoV-2 exposure and illness on IgA response after vaccination, we evaluated the change in serum anti-SARS-CoV-2 IgA following receipt of COVID-19 vaccination as part of a longitudinal serosurvey of first responders at high risk for SARS-Cov-2 infection. The gene discussed is CD79A; the disease is COVID-19.