Dynamics of anti-nucleocapsid and anti-spike antibodies elicited by SARS-CoV2 infection in a university setting

FLOR N; GARCIA MI; MOLINERI A; MIOTTI C; BOTTASSO O; DIEZ C; VEAUTE C

Mar del Plata

Congreso; LXX Reunión Anual de la SAI, 16-19 noviembre de 2022; 2022

Sociedad Argentina de Inmunología

This study assessed the dynamics of the SARS-CoV2 infection in workers and students at the FBCB-UNL. 188 individuals (53 male, 135 females, aged 18-67 y) were recruited from December 2021 to July 2022, and 3 blood samples were taken 1 month apart. Demographic and epidemiological information was registered for each sampling time. Anti-S antibody concentration (UI/mL) was quantitated by ELISA, whereas anti-N antibody levels were measured by ECLIA and expressed as Positivity Ratio (PR). A PR>1 indicates antigen exposure being used to identify individuals with previous infections. For statistical analysis, nonparametric tests were applied.Results are shown as median and interquartile range. Forty-two percent of the individuals reported being diagnosed before or during the study; however, anti-N levels indicated that 80% of theparticipants had been in contact with the virus. At recruitment, 60 individuals vaccinated with 3 doses were previously infected, 3 of them being reinfected throughout the study. Among individuals with 2 doses, 39 had the infection before recruitment, 4 became infected once, and 1 had 2 consecutive infections during the study. After 3-5 months of the second dose, the infected individuals with 2 doses of any vaccine had higher anti-S levels compared to those with noinfection (43346 [25110-99586] vs. 9135 [6714-18689] p