SARS-CoV-2: A Biochemical Treatise on its Past, Present & Future

The SARS-CoV-2 pandemic is unprecedented but equally unprecedented is the contribution of scientists who have helped us in understanding the mechanisms by which it infects human beings and also, developing a variety of vaccines to protect the masses, in a year’s time, which can be called truly groundbreaking. This article gives an overview of the progress made by scientists around the world working round the clock in developing an understanding of the SARS-CoV-2 evolution and COVID-19 disease pathogenesis, and also makes an attempt to suggest the possible ways of coping with this pandemic if we have to co-exist with it forever!

- Dr Ashok Kumar

As per the figures disclosed by the National Health Ministry (NHM), India has witnessed 400,000 excess deaths in April and May, 2021 in comparison with April and May 2020. And the surge in COVID-19, cases in Europe, the US and neighbouring countries reveals that the coronavirus is still amidst us and is thriving well! Since December 2019, with more than 188 million confirmed cases and more than 4.0 million deaths worldwide, as recorded on July 16, 2021, COVID-19 has severely disrupted human life, and we still don’t know for sure. The reasons why COVID-19 drastically affects some people, but the majority recovers whilst remaining largely asymptomatic. ‘How long will the immunity acquired after infection or the vaccination driven adaptive immunity be able to save us from reinfection?’ is a million-dollar question.

Why is SARS-CoV-2 so contagious?

Expedited sequencing of the viral genome, which proved that SAR-CoV-2 is similar to SARS (Severe Acute Respiratory Syndrome), the infection broke out in China between 2002 and 2004, also provided a clear understanding about the nature and mechanism by which SARS-CoV-2 spikes bind with Angiotensin-Converting Enzyme-2 (ACE-2), 10-20 times more effective than its predecessor, and how it gets quickly detached with the help of a protease allowing the lipid layer to fuse with the cell membrane and releasing its RNA into the host cell. Once inside, the virus replicates by simply hijacking the machinery of the host cells, thus spreading further and infecting more cells and eventually other organs, the transmission contaminating the environment and thus infecting more people. It’s again the understanding of the spike glycoproteins, which formed the basis for developing novel vaccines, in record times.