The SARS-CoV-2 virus causes COVID-19 disease, which was first diagnosed in late December 2019 among a few people with unknown respiratory illness in Wuhan city, Hubei province, China. Presumably this virus jumped from a natural host to human, and that occurred in one of the open food markets in Wuhan city, spreading very quickly to neighbouring provinces, neighbouring countries and eventually different continents. The World Health Organization declared the outbreak a Public Health Emergency of International Concern on 30 January 2020, and a pandemic on 11 March 2020. This virus killed over 5.5 million people globally as of 2021 and there is no sign of stopping with the latest addition of Omicron variant. However; SARS CoV-2 also forced us to invent new skills and technology not only to defeat it but also to propel ourselves forward. For instance, serological diagnostic tests in the form of Point of Care Test (POCT) format and regular EIA format become available in a couple of months instead of years.
Although molecular/ RT PCR become the test of choice for clinical diagnosis, serology has also limited uses for patient care in addition to Public Health (PH) uses. For PH, SARS-CoV-2 antibody testing is testing is essential for estimating population based seroprevalence and also to assess vaccine efficacy or responses which enable evidence-based decision making for public health recommendations. For clinical care, SARS CoV-2 antibody testing help select group of population where molecular/PCR test is negative. So it may help to increase case identification when used as an adjunct to routine molecular testing in those select cohorts; however, it is become challenging due to the emergence of new variants. So, in this presentation we will review serological testing of patients’ blood against SARS Cov-2 virus and highlight pros and cons of uses of serological testing in public health and its uses of clinical diagnosis.