The UK Health Security Agency's Chief Medical Adviser, Susan Hopkins, said this Sunday that they will begin trials of an antiviral pill against Merck's molnupiravir Covid-19 through drug testing later this month.

England was the first country in the world to approve last week the potentially revolutionary antiviral pill Covid-19. The drug was developed by Merck & Co Inc and Ridgeback Biotherapeutics of the United States.

In October, the government said it had secured 480,000 doses of Merck's drug, as well as 250,000 doses of an antiviral pill developed by Pfizer Inc.

"This is good news and its release will begin through a drug trial later this month/early December," Hopkins said, regarding the approval of molnupiravir.

Hopkins said that all trials to date had been done with the unvaccinated, so this would help to understand how it will work in the general vaccinated population.

"At some point, the new Pfizer drug will probably not be approved until next year, " he added. " It will likely still take a few months."