Pfizer may have an anti-viral COVID-19 pill available by the end of the year

Pfizer, which along with Moderna developed successful mRNA vaccines against COVID-19 late last year, announced on Tuesday that it could have ready by the end of the year an experimental oral drug which would treat COVID-19 as soon as patients display symptoms. The announcement was made by CEO Albert Bourla on the CNBC program "Squawk Box," who said that for the drug to be released to the public it will first need to perform well at clinical trials and receive approval by the Food and Drug Administration (FDA).

"This is an inhibitor of the protease enzyme in the SARS-CoV-2 which is promising in pre-clinical studies to block the ability of the virus to replicate," Dr. Monica Gandhi, infectious disease doctor and professor of medicine at the University of California — San Francisco, told Salon by email.

Pfizer had announced that Phase I trials, the first stage in testing a new drug, were to start soon to see if the virus was safe in adults.

Gandhi said that it was a "promising" oral antiviral drug, one that "could be used easily in the outpatient setting to treat COVID-19." Remdesivir is the only other existing antiviral drug used to fight COVID-19; famously, it was administered to President Trump when he contracted the virus.

Dr. Russell Medford, Chairman of the Center for Global Health Innovation and Global Health Crisis Coordination Center, said the drug held "significant promise as a potential treatment to be used at the first sign of infection or exposure to the SARS-CoV2 virus," with the caveat that the clinical trial process had barely begun.

"To have this drug available for broad use by the end of the year is very ambitious but not without precedent as exemplified by the extraordinary rapidity in which multiple COVID-19 vaccines were developed, tested and deployed," Medford added.

Because such a drug would be administered to those who contracted COVID-19, and thus were either unvaccinated or breakthrough cases, its utility may be slightly more limited than the vaccine. Dr. Alfred Sommer, dean emeritus and professor of epidemiology at Johns Hopkins University, noted that preventing a disease through a vaccination is more cost effective than treating it after a person has been infected and diagnosed.

Pfizer, like Moderna, currently distributes a vaccine using a revolutionary new technology called mRNA vaccines. While conventional vaccine platforms take a weak or dead version of a pathogen (disease-causing organism) and inject it into the body, mRNA vaccines simply use a bespoke RNA strand that trains the body's cells to recognize proteins associated with the microscopic invaders. In the case of their COVID-19 vaccine, the immune system is trained to recognize proteins associated with the spikes that poke out of the virus' central sphere like spines from a sea urchin.