Laboratory Based Preliminary Study on Anti-SARS-CoV-2 Antibody Response among State Sector Healthcare Workers in a Single District in Sri Lanka

Abstract

Background: Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is responsible for the current COVID-19 pandemic. Healthcare workers are one of the risk groups due to their strategic role in patient management. Presence of antiSARS-CoV-2antibodies in serum following seroconversion could be determined through antibody ELISA assay. Objectives: This study was to analyze the laboratory identified viral markers of Anti SARS-CoV-2 antibody in blood samples of health care workers to demonstrate the seroconversion to SARS-CoV-2 virus following exposures, natural infection or vaccination and to describe the sociodemographic, and clinical parameters among them. Study design: This laboratory based retrospective study was conducted at the National Virus Reference Laboratory (NVRL), at the Medical Research Institute (MRI). The study retrospectively analyzed 235 blood samples received to the NVRL, for testing of anti-SARS-CoV-2 antibody among health care workers in a one month period. All samples requested for anti-SARSCoV-2 antibody were tested with SARS-CoV-2 spike protein specific IgG antibody, and with SARS-CoV-2 Total Ab ELISA. The socio-demographic data were gathered through the request forms were also analyzed. Results: Total 235blood samples were tested for anti-SARS-CoV-2 antibody and 234(99.6%) were confirmed to have spike protein specific IgG antibody while 2% were confirmed to have Nucleo-capsid protein targeting antibodies of the positives, 100% were vaccinated with two doses of vaccine and 1% had positive PCR. Conclusion: The current study encounters a significantly high prevalence of vaccine induces SARS-CoV-2 antibody carriers among the healthcare workers in the study community.