Now, a Danish laboratory study has published results suggesting that atovaquone has a protective effect against coronavirus in human lung cells. Atovaquone is part of the antimalarial MalaroneTrusted Source, which doctors have used for the treatment and prevention of malaria since 1999.

Speaking to Medical News Today, Dr. William Schaffner, a professor of infectious diseases at the Vanderbilt University Medical Center, Nashville, TN, welcomed the study: “Everybody’s excited when a drug that’s been in use before [looks promising in the laboratory] because obviously, we have a great deal of clinical experience to back it up. It’s already licensed. But now we have to see if it really does work in people. That’s a giant step.”

The study by a team at Aarhus University found that atovaquone blocked infection from Alpha, Beta, and Delta variants of COVID-19 in human lung cells in vitro.

However, Dr. Schaffner urged caution: “Of course, it’s a laboratory study. Which means it is provocative but early. I hate to put it in the same category, but [I] was just thinking of another study that looked good in the lab but fizzled — the hydroxychloroquine studyTrusted Source.”

With Omicron spreading at an alarming rate and the global deaths from COVID-19 now well over 5 million, the hunt for effective treatments against COVID-19 is becoming ever-more urgent.

Scientists have considered many drugs, but few have realized any early promise. Even molnupiravir, hailed by many as a COVID-19 game-changer, does not seem to be living up to the hype. In clinical trials, the real-world efficacy in preventing severe COVID-19 symptoms is significantly lowerTrusted Source than initial trials suggested.

Monoclonal antibodies have some clinical benefits in preventing severe COVID-19 symptoms, but healthcare professionals have to administer them intravenously. In severely ill patients on ventilators, dexamethasone, an oral steroid, can reduce deaths from COVID-19 by up to a third.

So the search is still on for effective oral treatments that can prevent or minimize symptoms. Many researchers are testing licensed drugs that they might be able to repurpose to treat or prevent COVID-19.

• An antimalarial is the latest drug that researchers have identified as a potential COVID-19 treatment.
• In a laboratory study, scientists found that atovaquone inhibited replication of SARS-CoV-2 in human lung cells.
• The effects occurred in vitro against Alpha, Beta, and Delta variants.
• Clinical trials are necessary to see whether it is possible to repeat these results in people with COVID-19.