The Closest Related Virus to SARS-CoV-2 Has Just Been Discovered, And It's in Bats - ScienceAlert

Researchers have discovered coronaviruses lurking in Laotian bats that appear to be the closest known relatives to SARS-CoV-2, the virus that causes COVID-19, found to date, according to news reports.

In a new study, researchers from the Pasteur Institute in France and the University of Laos captured 645 bats from limestone caves in northern Laos and screened them for viruses related to SARS-CoV-2.

They found three viruses — which they dubbed BANAL-52, BANAL-103 and BANAL-236 — that infected horseshoe bats and shared more than 95% of their overall genome with SARS-CoV-2.

One of the viruses, BANAL-52, was 96.8% identical to SARS-CoV-2, according to Nature News.

That makes BANAL-52 more genetically similar to SARS-CoV-2 than any other known virus.

Previously, the closest known relative to SARS-CoV-2 was RaTG13, which was found in horseshoe bats in 2013 and shares 96.1% of its genome with SARS-CoV-2, Nature News reported.

What's more, all three of the newly discovered viruses are more similar to SARS-CoV-2 in a key part of their genome — called the receptor binding domain (RBD) — than other known viruses.

The three viruses could bind to ACE2 about as well as early strains of SARS-CoV-2 found in Wuhan, they said.

Still, even though the newly discovered viruses are closely related to SARS-CoV-2, all three viruses lack a sequence for what is known as the "furin cleavage site," which is seen in SARS-CoV-2 and aids the virus's entry into cells, according to Nature News.