The drug could be prescribed to patients at the first sign of infection

Pfizer, who developed the first authorised Covid vaccine along with BioNTech SA, have announced that they are in the process of developing an antiviral drug that has been shown to have an impact against the virus that causes COVID-19. As opposed to the vaccines which aim to stop people becoming infected with the virus, this new drug would be a way to treat a patient who has already been infected. The catchily-named PF-07321332, is a protease inhibitor, and has now begun an early-stage U.S. trial after positive lab studies. https://twitter.com/CNBCnow/status/1374376422932848652 Protease inhibitors prevent the virus they are aimed at treating from replicating in cells, and are currently used to treat other viral pathogens such as HIV and hepatitis C. At the same time, Pfizer is working on a treatment to be administered intravenously, with the aim that this be used in tandem with the oral treatment. The drugmaker's Chief Medical Officer Mikael Dolsten said in a statement that the two treatment candidates together "have the potential to create an end-to-end treatment paradigm that complements vaccination in cases where disease still occurs.” At the moment, two rival oral antiviral treatments are ahead of the Pfizer candidate and are in mid-stage trials. Currently only one drug has been approved by the US Food and Drug Administration for the treatment of COVID-19 - Gilead Sciences's remdesivir. It would therefore be a huge boost if any of these therapies currently in trail could be approved as well, and would be another major step in the battle against COVID-19.