There is a hot debate around origin of SARS-CoV-2, whether the novel coronavirus natural or manmade? Findings of certain scientists resulted that coronavirus is recombination of two viruses from bats and pangolins.
Scientists are in search of question about origin of novel coronavirus natural or manmade, but the analysis of genome sequence data from SARS-CoV-2 and other related viruses couldn’t find any evidence of its engineering or made in laboratory claim.
The novel coronavirus (SARS-CoV-2) could be a chimera of two pre-existing viruses, which means it could be a combination of two different viruses. Scientists believe that both pre-existing viruses may have infected a single organism at the same time and recombined to form the novel coronavirus.
The recombinant virus has the potential to infect new host species. Since the outbreak, different coronaviruses have been discovered in different bats and in pangolins species.
A study shows that the genetic sequence of a virus identified in one bat specie is 96 per cent similar to that of the novel coronavirus, which indicates that bats could be the reservoir of Covid-19 coronavirus.
Researchers also found a similar virus to the current coronavirus in pangolins. The virus in pangolins has a 99 per cent genomic similarity in the region that allows the virus to enter human cells to infect them. In the bat’s species, this region has only 77 per cent similarity.
These studies suggest that two viruses, one in bat and another in pangolin may have recombined which resulted in new SARS-CoV-2. For this recombination to occur, both the viruses should have infected the same organism at the same time.
It is still unclear that in which organism this recombination occurred. Despite the fact that SARS-CoV-2 originated in animals. It is effective in causing diseases in humans.
Several features of SARS-CoV-2 makes it very successful in causing the epidemic.
Coronaviruses are surrounded by a halo of spiky proteins. These spiky proteins stick out like tips on a crown and helps the virus attach itself and gain entry into the host cell.
The spikes recognize and stick to a receptor protein called ACE2, which is found on the surface of human cells. The spikes of SARS-CoV-2 allows it to stick to our cells far more effectively than other types of coronaviruses.
Most respiratory viruses infect either the upper or lower airways. In the case of new coronavirus, both upper and lower airways are infected. Some types of viruses are highly contagious, while other viruses are less contagious.
The novel coronavirus spreads between people before any symptoms show up, which makes it easy for the virus to transmit to multiple hosts and makes it difficult for scientists to identify and control it.