A RELIEF OR ADDED THREAT FOR INDIA?

Researchers across the globe have observed that there may be a unique mutation in the viral strain infecting the Indian population. And may be that is the reason why few countries are suffering large numbers of fatalities as compared to India.

- Dr Manbeena Chawla

In December 2019, several cases of pneumonia of unknown etiology were reported in Wuhan, Hubei Province, China. The disease which is now called COVID-19 is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was discovered through whole-genome sequencing, polymerase chain reaction (PCR) and culture of bronchoalveolar lavage fluid obtained from affected patients.

Soon after, Chinese researchers revealed that the virus is 96 per cent identical at the whole-genome level to a bat coronavirus. The researchers also announced that the virus uses a same cell entry receptor, angiotensin-converting enzyme 2 (ACE2), for its entry into the host. A spike glycoprotein found on the surface of SARS-CoV-2 is a class I fusion protein which helps the virus in its initial attachment with human ACE2 receptor and its consecutive fusion with the host cells. The attachment is mediated by the S1 subunit of theprotein via its receptor-binding domain.

Simultaneously, researchers across the globe started conducting similar studies to understand how exactly this virus is attacking the humans. Researchers also started studying the infection pattern of this virus in different countries and came out with the finding that there may be a unique mutation in the viral strain infecting the Indian population. And may be that is the reason why few countries are suffering large numbers of fatalities as compared to India.

Researchers from Taiwan and Australia have apparently found a coronavirus strain isolated in India carrying mutations in the spike protein’s receptor-binding domain (RBD) of the virus. A computer simulation shows that the RBD mutation that was not found in any other variants across the world, could remove a hydrogen bond from the spike protein. In the absence of this bond, the virus is less likely to bind to ACE2 that is found in the lungs and other organs.