Introducing molnupiravir.

Recently, the American pharmaceutical company Merck came with promising news. They turned out to be developing a surprisingly effective antiviral drug that could be an important asset in our fight against the coronavirus. This ‘miracle pill’ against corona, called molnupiravir, may soon also be reviewed by the European Medicines Agency (EMA). But is all this excitement about the pill justified? And what does the emergence of this pill mean for existing vaccines?

Molnupiravir

Let’s start at the beginning. Because what exactly is molnupiravir? “Molnupiravir is an experimental drug that is administered orally,” says virologist Vinod Balasubramaniam. “It then inhibits SARS-CoV-2 replication; the causative agent of COVID-19.” This means that the virus can no longer reproduce as easily, which significantly reduces the chance that you will end up in hospital or die from the disease after a positive test. “It reduces the risk of hospitalization or death by 50 percent, an interim analysis of a clinical trial showed,” said Balasubramaniam. In addition, the ‘miracle pill’ seems to work against the most common corona variants.

Treatments

They are encouraging results. Because at the moment there are not many effective treatments against COVID-19. “The treatments out there are often expensive, difficult to administer, not yet widely available or only marginally effective,” explains Balasubramaniam. “Molnupiravir, originally developed to treat the flu, could solve many of these challenges.” Once you have been diagnosed with COVID-19, you should start taking the pill twice a day for five days as soon as possible. Since it is only a pill, the patient does not have to come to the hospital, which is of course a lot easier than other COVID-19 treatments, which require expensive intravenous transfusions. “This reduces the chance of an infected person transmitting the virus to medical personnel and prevents potential complications associated with transfusions,” Balasubramaniam points out.

How does it work?
The SARS-CoV-2 virus, which causes COVID-19, is a so-called RNA virus. It makes copies of itself by encoding instructions on RNA, which is made up of “base” molecules, namely cytosine, guanine, adenine, and uracil, also abbreviated as C, G, A, and U. molnupiravir can then make U (uracil) or mimic C (cytosine). When the virus then incorporates this into its RNA, the drug causes genetic mutations that hinder the virus. Crucially, the drug can fool the virus, but not human cells. This means that molnupiravir has a targeted effect and leaves the human cells alone for the most part. As a result, no specific side effects of molnupiravir have yet been discovered.

According to Merck, the drug could become an important asset in our ongoing fight against the coronavirus. “Many countries still don’t have enough access to vaccines,” Balasubramaniam says. “And the unvaccinated still make up the majority of hospitalizations and deaths around the world. Treatments for COVID-19 therefore remain an essential part of our response to the pandemic. However, developing new drugs to treat a disease is expensive and time-consuming. Therefore, ready-to-use drugs that were already considered safe for use against other conditions are being considered. While Molnupiravir requires more testing and assessment, it also offers the opportunity for a stronger, more targeted approach.”

Vaccines

That also raises another pressing question. Because what does the emergence of this ‘miracle pill’ mean for existing vaccines? Can we delete it? “This is a very important issue to understand,” emphasizes Balasubramaniam. “Vaccines remain the ultimate shield for our fight against the pandemic. Vaccines provide long-lasting and robust protection against COVID-19 before the infection itself has arrived. They train our bodies to one day be ready to fight this disease. And that’s something an antiviral pill can’t provide. Vaccination and additional ‘booster shots’ (for certain individuals) should therefore remain a priority for governments around the world in the fight against the pandemic.”

“Vaccines remain the ultimate shield for our fight against the pandemic”

Difference

However, according to the virologist, it is a good step that a working and effective drug is added to our ‘weapons’ to fight COVID-19 and future pandemics. In addition, molnupiravir appears to be able to make a big difference. “For people with a mild form of COVID-19, it could prevent progression to a more serious, even life-threatening disease,” Balasubramaniam said. “In that respect, it could be an alternative approach to prevent severe forms in people who do not want to be vaccinated or people who do not respond well to vaccines and, for example, have a severely weakened immune system.”

Despite the promising results, some caution is still in order at this point. “We have to be careful with the results,” Balasubramaniam says. “We have limited research results so far. But if the findings pass additional scientific research and molnupiravir also proves effective in a larger population, this will be very big news. As the current study data has only been done in unvaccinated individuals, it remains to be seen how the drug will respond in vaccinated individuals suffering from breakthrough infections (showing severe symptoms). But so far it is all very promising.”