IgA antibody dynamics in healthcare workers after CoronaVac (R) vaccination and heterologous Comirnaty (R) booster dose

BackgroundThis study is aimed at calculating the IgA antibody dynamic range in healthcare workers (HCWs) after immunization with CoronaVac (R) and Comirnaty (R) booster dose.MethodsA total of 118 HCW serum samples from Southern Brazil were collected the day before the first vaccine dose (day 0) and + 20, + 40, + 110, + 200 days following the vaccine's first dose, and + 15 days after a Comirnaty (R) booster dose. Immunoglobulin A (IgA) was quantified using immunoassays for anti-S1 (spike) protein antibodies (Euroimmun, Lubeck, Germany).ResultsSeroconversion for the S1 protein occurred in 75 (63.56%) and 115 (97.47%) HCWs by day + 40 and day + 15 after the booster dose, respectively. There was an absence of IgA antibodies after the booster dose in two (1.69%) HCWs undergoing biannual rituximab administration and one (0.85%) HCW for no apparent reason.ConclusionComplete vaccination showed a significant IgA antibody production response, and the booster dose considerably increased this response.