Serosurveillance of COVID-19 amongst health care workers in a teaching institution - A prospective cohort study in Puducherry district.

Introduction: The rapid spread and mutation rate of severe acute respiratory syndrome corona virus (SARS-CoV2) demands continuous monitoring in terms of genomic and serosurvival. The current study is designed to track the seroprevalence of health care workers (HCWs) postvaccination, as they may be more susceptible to contracting the SARS-CoV-2 infection compared to the general population. Objective: The objective was to identify the seroprevalence rate for SARS-CoV-2 immunoglobulin G (IgG) antibody (N, S1, S2) amongst HCWs of various levels of exposure working in a tertiary care teaching hospital in Puducherry. Materials and Methods: The present study followed a nonprobability consecutive sampling technique, which involved 216 study participants HCWs from the hospital. IgG antibody levels were measured using EUROIMMUNE Anti SARS-COV-2 ELISA KIT (IG g) ELISA at two points: firstly, 2 weeks after the second dose of vaccination, followed by 2 weeks after the booster dose. Results: Out of the total 216 participants enrolled in the survey, there were 140 males and 76 females, and the maximum number of candidates studied were in the 41-50 age group. Almost 46.7% of the HCWs who participated in the study were seropositive for SARS-CoV-2 in the case of those who were high-risk exposed, while only 30.4% were amongst those who were low-risk exposed. The proportion of study participants who became seropositive increased considerably after the booster dose (65.7%), from 38.0% when tested three months after infection. Conclusion: A significant increase in antibody titres amongst high-risk HCWs postboost vaccination demands continuous monitoring of soluble IgG levels for recommendations of vaccination schedules.