Two different oral treatments for preventing newly diagnosed patients with COVID-19 from hospitalization and death have been developed by the pharmaceutical giants Merck and Pfizer. These drugs will be valuable weapons in the war against COVID-19, making it less lethal.

According to STAT News, the medications work in entirely different ways. The Merck drug, called molnupiravir, was created with Ridgeback Therapeutics. In trials it reduced hospitalization by 50% and totally prevented deaths when given within five days of the onset of COVID-19 symptoms.

It’s a 40-pill regimen given over a course of five days. Molnupiravir works by tripping up the virus’s ability to replicate itself, so the infection has little chance of becoming severe and causing the immune system to go haywire. According to NBC News molnupiravir causes the enzyme that helps replicate the virus to make so many errors that the pathogen can’t reproduce. This reduces the viral load and infection time in order to prevent a dangerous immune response that could lead to serious illness and death.

The mechanism that molnupiravir uses is similar to the drug remdesivir, the only COVID-19 drug approved by the Food and Drug Administration (FDA), so it’s not a totally new formula. The advantage of the Merck drug is that it is a convenient pill, while administering remdesivir is done intravenously, in a hospital or clinical setting over several days, after patients are really sick, says The Atlantic.

Pfizer’s drug, called Paxlovid, is also a convenient pill but acts at a completely different point in the virus’s reproductive process. It allows the virus to reproduce its RNA but then shuts it down by binding to an enzyme called a protease. Without a working protease, the COVID-19 virus can’t make functional copies. According to STAT News, protease inhibitors have been used for years in drugs for HIV and hepatitis C, as well as cancer drugs. Paxlovid is taken with another drug called ritonavir, which blocks the liver from rejecting it. According to STAT News, Paxlovid reduced hospitalization by 89% and prevented death from COVID-19 in its clinical trials. Patients must begin taking Paxlovid within five days of the first symptoms and 30 pills are taken over a five-day period.

The pills are similar in that study results found they both are 100% effective against death due to COVID-19. And the rate of side effects was also similar. Fewer patients left the treatment groups compared to the placebo groups due to side effects.

Merck released the results of its study in October, and the data will be reviewed by an advisory panel of the FDA in December. So conceivably, the pill will have authorization by the end of this year. Pfizer requested authorization from the FDA for Paxlovid on November 15, so it could launch in December.