The Science Of Antiviral Medications

"Within three days of the symptoms, you have now 89% protection from disease leading to hospitalization with our medicines, and the data indicate 100% protection from death," says Pfizer's Chief Scientific Officer Dr. Mikael Dolsten.

A breakthrough moment in the fight against COVID: A life-saving treatment involving a simple pill that doesn't require a trip to the hospital. Here's how Pfizer described it.  

"The first in class oral protease inhibitor, which is a medicine taken as a pill for five days and inhibits one of the critical components of the virus, the SARS-CoV-2 virus, causing COVID-19, making it impossible for the virus to further expand," Dolsten said.

So what does all of that mean? A protease inhibitor is an antiviral drug commonly used to treat HIV. Scientists use that same concept here. The drug blocks protease enzymes.

Protease enzymes are like scissors that cut protein chains. This is how many viruses including this coronavirus replicate.   

Protease inhibitors basically stop those scissor blades, preventing them from cutting those chains, stopping the virus from multiplying.  

"I think this is one of the biggest medical advances for a single drug in virology in a long, long time," Dolsten said.