After the emergence of coronavirus disease-19 (COVID-19) in late 2019
spread to different countries, becoming a global health concern. It belongs to the
betacoronavirus family notorious for causing two outbreaks of severe acute respiratory
syndrome (SARS-CoV) and the Middle East respiratory syndrome (MERS-CoV) in the
last decade, causing huge morbidities and mortalities in a large number of population.
For the current pandemic of COVID-19, accurate and precise diagnosis and
surveillance of the infected individuals must be tackled by providing healthcare
facilities and preventive measures in hotspot regions. COVID-19 patients were
observed with non-specific symptoms like dry cough, sore throat, and fever in the early
phase of infection that can worsen to serve acute respiratory syndrome and shock in the
later phase of infection. Besides clinical symptoms, the radiographical finding of lungs
and other definitive tests like real-time-polymerase chain reaction (RT-PCR) confirms
the presence of a causative agent of COVID-19. After the infection of COVID-19, the
human immune system activates and tries to neutralize the infection by forming virusspecific
neutralizing antibodies. These antibodies can be detected in the patient's serum
and can serve as the diagnostic biomarker. Several different types of serological assays,
including enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay,
chemiluminescence enzyme immunoassays, immunofluorescence assay, and lateral
flow immune assay, used to detect the presence of antibodies in the serum of infected
individuals. This chapter will focus on the quantitative and qualitative determination of
SARS-CoV-2 specific antibodies by different serological assays like ELISA in
COVID-19 patients.
Keywords: Antibodies, COVID-19, ELISA, Severe Acute Respiratory
Syndrome-2, Serological Tests.