Age group-wise highest seropositivity was observed between 31 and 40 years age group (9.2%) with odds of seropositivity 1.4 occasions that of reference category (20C30 years). size was 377. Inclusion criteria were all staff reporting to the institute from different says and districts. Exclusion criteria-Any staff reported for a short visit of smaller than 14 days. Demographic details EVP-6124 hydrochloride and details of any likely exposure to a confirmed COVID-19 case were noted. A blood sample was collected, and serological assessments were carried out using ErbaLisa COVID-19 IgG kit by Calbiotech, as per the manufacturer’s instructions. Results EVP-6124 hydrochloride Overall seropositivity of IgG COVID-19 antibodies was 7.5% (31/413) (95% CI: 5.3C10.4%). Study populace (n?=?413) comprised of an adult populace in the age range of 21 yearsC53 years, and the mean age was 31.4 years (SD?=?6.2 years). Conclusion As the staff joining the institute have come from various parts of the country the study provides an estimation of antibodies against COVID-19. strong class=”kwd-title” Keywords: Antibody, Pandemic, Epidemiology, Serology Introduction Since December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has captured global attention and has become a worldwide pandemic.1 Due to its quick spread and easy transmissibility, you will find over 32 million positive cases and nearly a million deaths already.2 The World Health Organisation (WHO) India situation statement as of 21 Sep 2020 reported 5,400,619 confirmed cases and 86,752 deaths.3 Being a novel virus, research is lacking about its immunobiology and more studies are needed.4 WHO has emphasised research on this novel pathogen to chart out a roadmap for the pandemic, including populace serosurveys.5 Seroepidemiological surveys give an insight into the humoral antibody response of the population and predict trends.6,7 According to the WHO, around eighty percent of the new cases are mild or asymptomatic.8,9 The detection of such cases in the community is important in preventing the spread of the virus.10 Currently, the methodology for identifying the at-risk individual is by self-declaration, wherein the person gives a history of having had an exposure to or contact with a COVID positive case and is then screened for symptoms or via contact tracing. However, asymptomatic individuals may go undetected, unaware of contamination as they may have developed only moderate symptoms or none. However, they may have shed the computer virus even before symptom onset.11 The current diagnosis of COVID-19 infection relies on molecular techniques such as the reverse transcription real-time polymerase chain reaction (rRT-PCR).12 While molecular assays are the platinum standard for detecting acute infections, serological assays such EVP-6124 hydrochloride as TSLPR the Enzyme-linked Immunosorbent Assay (ELISA) can detect antibodies indicating recent contamination or prior exposure to the computer virus.13 In the early stages post symptom onset, IgG ELISA detection is low (4%C57%), it increases in the intermediate stage (54%C88%), and after 14?days, it is between 91% and 100%.14 EVP-6124 hydrochloride Thus, serological studies conducted on a mass level for antibody detection may provide information regarding disease prevalence in a populace.15 This may be used to assess the immune response and the herd immunity of a population.16 The Spike (S) protein and the Nucleocapsid (N) protein of the virus may be targeted by these antibody assays, primarily as they are conserved in nature.17 The indigenous serological assay recommended by the Indian Council of Medical Research (ICMR)?is the ELISA-based IgG kit developed by the National Institute of Virology (NIV), which detects IgG antibodies two weeks post-infection.18 Antibody surveillance studies and serosurveys strengthen public health mitigation measures and have to be conducted during the changing landscape of an evolving pandemic.19 A serosurvey conducted during the early months of the pandemic by ICMR reported that 0.73% of the surveyed populace experienced antibodies to SARS-CoV-2.20 However, as the pandemic spreads across the subcontinent and lockdown restrictions ease in the country, surveys will have to be done in the community, as well as in targeted populations to map out the changing styles and extent of infection.21 Being a central teaching institute gave the unique opportunity to estimate the antibody response in individuals, mostly healthcare workers who returned to the institute post lockdown from various parts of the country. Hence this sero-surveillance study using ELISA IgG is an assessment of seropositivity in this unique cohort. Materials and methods This study was a cross-sectional descriptive study. Institutional ethical clearance was taken. Informed consent was taken for participation in the study. The study populace included all staff reporting back to the institute post lockdown. The duration of the study was two months (16 June to 16 August 2020). The sample size was calculated assuming the prevalence of COVID-19 in the general populace to be 1% with the complete precision of 0.5% and 5% level of significance and finite correction for the population of 500; the study sample size was calculated as.