Antigen Testing in ELISA
Unlike any other viral infection, COVID-19 brought in its own set of challenges. The virulence, pathogenicity of the antigens was unknown. Although a member of the Coronavirus family, SARS-CoV-2 was novel in every form of the infection. The last decade saw pandemics from this family of viruses but never had the severity of the virus comprehended in such a manner.
The rate of infection and mortality was in check in the first wave of the disease when it hit the Indian shores in 2020 and was due to the prevalence of only one strain. Yet intermittent relaxations in lockdown and migration of people across the continents helped spread the virus all around. It also allowed the virus to mutate more, and the Delta strain then created havoc in the second wave. The infection had now made ingress into the rural landscape of the country. The spread resulted in a significant rise in cases. A large number of casualties also happened. The antigenic proteins are crucial for the spread of viral infection. In the case of SARS-CoV-2, the major antigenic proteins responsible were Spike (S), Nucleocapsid (N), Membrane (M), and Envelope (E) proteins. Spike was the most lethal, but with the appearance of new strains, other proteins have proved their lethality.
It is for this severity of antigens; it becomes rational enough to screen the patients for the presence of the antigens in the system. The antigens reach their peak on the fifth day from the onset of infection. The antigens get flushed out by the eighth day with the production of antibodies. Thus, it’s easy to screen symptomatic individuals but a challenge for those who are asymptomatic. To address this, the government-mandated antigenic testing with confirmation on RT-PCR. Antigen testing by Rapid cards has been the norm since the start of the pandemic. Though these cards serve as Point of Care Testing devices, they are prone to discrepancies if not done by an expert and if it’s out of the window period. Antigen testing by ELISA is one such method that provides the more specific result with precision.
J Mitra & Co took the challenge of developing an early detection antigen kit. With the help of in-house research and development, it succeeded in making the COVID-19 ELISA Antigen kit. The authorities approve the kit, and various reputed institutes have evaluated this. The Sensitivity and Specificity of the kits are high, and their performance is at par with RT-PCR. The testing helps humankind’s most affordable and reliable testing.