On Thursday, Britain’s medicine regulators approved an antiviral pill that could be effective at treating Covid-19. This new discovery is said to be a potentially game-changing way of treating the coronavirus.

The regulator said that it had approved the world’s first antiviral oral pill called Molnupiravir. Research showed that the pill is “safe and effective at reducing the risk of hospitalization and death in people with mild to moderate Covid-19 who are at increased risk of developing severe disease.” Britain is the first country in the world to approve the drug.

Molnupiravir was developed jointly by Ridgeback Biotherapeutics and Merck. According to the U.K. ‘s Medicines and Healthcare products Regulatory Agency, the pill interferes with the virus’ replication. This stops it from multiplying, and keeps virus levels low in the body, reducing the severity of the disease. Molnupiravir can also be administered outside of a hospital.

The MHRA stated that the decision “follows a rigorous review of its safety, quality and effectiveness” and made it the “first oral antiviral for the treatment of Covid-19 to be approved.”

Clinical trial data shows that the oral pill is the most effective when taken during the early stages of infection. The British regulator recommended its administration as soon as possible following a positive Covid test or within five days of the onset of symptoms.

The pill has been authorized for use in patients who have at least one risk factor for developing severe illness, such as diabetes mellitus, obesity, or heart disease, for anyone over the age of 60 and for those who have mild to moderate Covid.

The U.K.’s Health secretary, Sajid Javid, stated that it’s a “historic day for our country as the U.K. is now the first country in the world to approve an antiviral that can be taken at home for COVID-19.”

“This will be a gamechanger for the most vulnerable and the immunosuppressed, who will soon be able to receive the ground-breaking treatment,” he continued in a statement.