How many coronaviruses are there? What gen sars-cov 2?

Coronaviruses are a group of viruses that cause disease in mammals, including humans and birds. Coronavirus includes viruses of the subfamily Coronavirinae in the Coronaviridae family, according to the Nidovirales order.

The Coronavirus family is classified into four genera: Alpha, Beta, Gamma and Delta Coronavirus.

Coronavirus is everywhere. Alpha coronaviruses and Beta coronaviruses can infect mammals while Gamma coronaviruses and Delta coronaviruses infect birds, but some of them can infect mammals.

So far there are 7 types of human pathogenic coronavirus (HCoV) belonging to 2 of these genera:

1. Alphacoronavirus includes: HCoV-229E and HCoV-NL63.
2. Betacoronavirus includes: HCoV-HKU1, HCoV-OC43.

Some coronaviruses can evolve and potentially cause disease in humans such as SARS-CoV (2003), MERS-CoV strains and most recently, the Wuhan pneumonia virus 2019-nCoV, new name SARS-CoV- 2.

SARS-CoV-2

SARS-CoV-2 began to appear and spread from the end of 2019.

The whole genome analysis of SARS-CoV-2 shows that this is a Betacoronavirus, in a group different from the Betacoronavirus related to severe acute respiratory syndrome in humans (SARS) and Central respiratory syndrome. East (MERS).

The scientists discovered that RaTG13, a variant virus from a bat of the Rhinolophus affinis species in China's Yunnan province, has a 96% sequence of genomes similar to SARS-CoV-2.

Later, scientists found that SARS-CoV-2 was even more closely related to the pangolin virus, whose genome was 99% similar. This suggests that pangolin may be the more ideal host for infection than bats. However, a new study shows that the genome of the corona virus isolated from Malaysian pangolin is only 90% similar to SARS-CoV-2. Thus, virus isolation on pangolin is not the cause of Covid-19.

However, the corona virus isolated from pangolin is 99% similar to the S protein region that allows direct transmission to humans. In contrast, the RaTG13 virus isolated from bats is not likely to infect humans.

In addition, comparisons of this genome indicate that SARS-Cov-2 virus is the result of a recombination of two different viruses, one close to RaTG13 and the other close to the virus on pangolin.

In other words, SARS-CoV-2 is a combination of two viruses found in bats and pangolin.

It is important now to find out that a new host species capable of carrying the SARS-CoV-2 virus is a combination of the two. And above all, scientists need to know the environment that promotes the combination that creates the Covid-19 virus.