From developing a vaccine to experimenting with new drugs, pharmaceutical companies have been rushing to search for a miracle cure that could put a quick end to the pandemic. It started with prospects of a vaccine, yet, with the success of several companies including Pfizer, Moderna, and Johnson & Johnson, that race came to a close. Now, eyes are turning to a new COVID-19 pill, called molnupiravir, created by the company Merck.

Who is Merck?

Merck & Co., known as MSD outside the United States and Canada, is a manufacturer of several well-known pharmaceutical products. Founded in the US in 1891, Merck has accomplished numerous feats in its over 130-year existence, including the synthesis of vitamin B1 in 1936, the development and distribution of an MMR (measles-mumps-rubella) vaccine in 1971, and more recently, the development of the new oral COVID-19 drug molnupiravir.

What is the drug?

Unlike vaccines that act as a preventative measure against COVID-19, molnupiravir is taken after symptoms appear to reduce the rate of hospitalization. The drug works by inhibiting the virus’ ability to replicate, thus diminishing the symptoms and reducing the severity of the disease. When the drug enters the body, the active molecule, molnupiravir, incorporates itself into the virus’ genetic material as it is being copied. “This results in many mutations, or changes in the RNA genetic code, introduced into the viral RNA,” says Dr. Shaw, a Harvard Ph.D. and infectious diseases expert. “And when this RNA is translated into viral proteins, these proteins contain too many mutations for the virus to function [4].”

However, doctors warn against molnupiravir drawing attention away from COVID-19 vaccinations. Despite its ability to drastically reduce hospitalization rates, vaccinations are still essential to slow the virus’ spread and prevent initial infections.

Clinical trials

In a clinical trial conducted before October, the pill was found to reduce hospital admission rates by half. The 775 participants were all unvaccinated and had laboratory-confirmed symptomatic COVID-19, and were part of a higher risk group due to factors such as obesity, diabetes, or being over 60 years of age[15]. An interim analysis of a phase 3 study showed that 14.1% of those who took a placebo were hospitalized or died by day 29. No deaths were reported in patients who were given molnupiravir within the 29-day period, and only 7.3% of those who took molnupiravir were hospitalized. The clinical trial was cut short following its success in order to move forward faster.

Side effects

According to the trials conducted, molnupiravir appears to have a clean safety record. Additionally, Merck reportedly has evidence that the drug does not cause mutations in humans. However, there is concern that the drug may adversely affect groups of people, especially pregnant women, that were omitted from the trial. Specifically, it is unknown if molnupiravir will interfere in the RNA replication necessary for fetal development, causing birth defects[4].

Yale Medicine infectious diseases expert Jaimie Meyer, MD, MS, noted that “In the trial, not only did they exclude women who were pregnant, breastfeeding, or anticipating becoming pregnant, but they also told the men enrolled in the trial that they couldn’t have unprotected sex with women for a week after they were done with their medication[4].”

Drug Release

As Merck continues to push for approval for molnupiravir, the U.K. becomes the first country to authorize its public usage, though only for those who are of or above the age of eighteen and have at least one risk factor for developing severe disease [1]. The pill is meant to be taken twice per day over a period of five days by people who had tested positive for COVID-19 and had mild to moderate symptoms.

The U.K. announced in late October that it had obtained 480,000 five-day courses of the 10 million Merck has said they will be able to curate by the end of the year.

“We are working at pace across the government and with the NHS to set out plans to deploy molnupiravir to patients through a national study as soon as possible,” said Britain’s health secretary, Sajid Javid, referring to the U.K.’s National Health Service[1].

In Canada, molnupiravir is still being reviewed by Health Canada. The federal regulator said it continues to receive data “as new information becomes available” from Merck; however, no timeline was given. In addition, the regulator said that the review will weigh the benefits against risks and put molnupiravir against strict safety, efficacy, and quality measures[2].

Merck added that a supply agreement was not yet reached but negotiations were still taking place. “We remain committed to working with the government to ensure Canadians will have access to our medicine should it receive market authorization by Health Canada,” Merck said in an email from its media centre[2].

Across the globe, the Japanese government has reached a deal to purchase, upon authorization, 1.6 million courses of molnupiravir. Merck is continuing to request clearance for the drug across the world for adults with mild to moderate symptoms of COVID-19 and at risk for severe disease[1].


With the expense of the drug totalling $700 for a single five-day course, many are questioning whether or not molnupiravir will be accessible to lower-income individuals. As a response, in April, Merck entered into an agreement with 5 Indian generics manufacturers—enabling them to create the drug molnupiravir—in an effort to boost the availability of the antiviral drug[5].

However, there are still concerns that developing countries may be left behind as wealthier countries continue to buy up stock. A number of countries, including the US, New Zealand, and Australia, have already secured orders with Merck for the drug.

In an effort to address the growing concern, Merck has planned to create a tiered pricing system, where pricing of the drug is based on the country’s ability to finance fighting the pandemic. The company has also worked to fulfill the growing demand for molnupiravir, aiming to produce at least 20 million treatment courses by 2022[5].


Recently, Pfizer has also created their own antiviral COVID-19 pill. In its earlier clinical trial, the pill reportedly reduced hospitalization rates by between 85 and 89 percent[11].

Health Canada has not yet received a sample of the drug but said in an email to CBC News that if they received one, “it will be reviewed on a priority basis”[11].

On 16 November 2021, Pfizer signed a deal with an UN-backed group enabling others to make its COVID-19 pill. 

Additionally, the company said it would grant a license to the Medicines Patent Pool, enabling 95 countries and over half the world population to have access to the drug[11].