Since it started spreading in Wuhan, China back in December 2019, the coronavirus has mutated into 10 different types and now one of them -the A2a- has nearly replaced all other types of the virus across the world, says a study conducted at the National Institute of Biomedical Genomics in India.
The study, by Nidhan Biswas and Partha Majumder from the National Institute of Biomedical Genomics in Kalyani, West Bengal, will soon be published in the Indian Journal of Medical Research, a medical journal run by Indian Council for Medical Research (ICMR), The Times of India reported.
The A2a coronavirus is highly efficient in entering the lung cells in large numbers. The A2a is hence easily transferable resulting in the rapid spread of the coronavirus across the world, the authors of the report wrote. According to them, the study is crucial as it provides vaccine developers with a specific target. "It (A2a) has become the dominant type of SARS-CoV2," said Majumder.
The research team has used RNA sequences of over 3,600 coronaviruses collected from 55 countries from December 2019 to April 6, 2020, for their study. The first observation was that the coronavirus had evolved into multiple types during its initial spread in China and the rest of the world. "The coronavirus can be classified into many types --- O, A2, A2a, A3, B, B1, and so on. Currently, there are 11 types, including type O which is the 'ancestral type' that originated in Wuhan," said Majumder to the daily.
According to the research, a certain form of mutation in the coronavirus allows it to be transmitted more efficiently from one person to another. "Such mutant viruses increase the frequency (of transmission) and sometimes completely replace the original type of the virus. The SARS-CoV2 is doing just that," Majumder added.
The researchers have concluded that the A2a mutation has altered a complement of the spike protein of the coronavirus which allows the virus to bind itself more easily to the surface of cells in the lungs.
Out of all the samples collected in India for RNA sequencing, 47.5 per cent contained the A2a coronavirus. More persons with type A2a have no known travel history to countries outside India. More samples need to be tested to draw more definite conclusions.