A new discovery from our Peter Kasson, MD, PhD, may help explain how coronaviruses are so adept at jumping from species to species. The findings will also help scientists predict how COVID-19 will evolve.
In a surprising discovery, Professor Kasson found that COVID-19 can use multiple “doors” to enter cells. Scientists have known that the virus that causes COVID-19, SARS-CoV-2, hijacks a protein called ACE2 to infect human cells. But Professor Kasson and his team determined that ACE2 wasn't essential for infection. ACE2 was the most efficient route for the virus, but it wasn't the only route.
That suggests that SARS-CoV-2 can even infect cells without any ACE2 receptors at all. And that versatility helps explain why coronaviruses are so nimble at leaping from species to species.
“The virus that causes COVID-19 uses ACE2 as the front door to infect cells, but we’ve found that if the front door is blocked, it can also use the back door or the windows,” Professor Kasson told me. “This means the virus can keep spreading as it infects a new species until it adapts to use a particular species’ front door. So we have to watch out for new viruses doing the same thing to infect us.”