Positive clinical trial findings for Merck & Co.'s experimental antiviral COVID-19 pill rippled throughout the healthcare industry last week on Friday, skyrocketing the pharmaceutical company's stock price while hurting the stock price of vaccine firms and producers of other coronavirus treatments.

Merck shares rose 12.3 percent to their highest level since February 2020 after research revealed that the company's pill called Molnupiravir might cut COVID-19 deaths and hospitalizations by half. Scientists welcomed the finding as possibly a breakthrough in the fight against COVID-19.

Meanwhile, vaccine producers such as Moderna Inc, Pfizer Inc, and its partner BioNTech SE saw their stock prices plummet. Moderna shares fell 13%, while Pfizer, which is developing its own COVID-19 pill, dropped 1.3 percent. Shares of BioNTech, AstraZeneca, and Novavax fell 11%, 2%, and 16%, respectively, in the United States.

Similar companies that sell other COVID-19 intravenous or injectable treatments traded down as well; for instance, Regeneron Pharmaceuticals Inc went down almost 5%, and Gilead Sciences Inc dropped around 2%.

Molnupiravir, in its oral form, has the potential to be a game-changer both in terms of treatment and prevention of Covid-19.

Merck is undertaking a late-stage experiment to determine if its antiviral pill may prevent COVID-19 infection, in addition to the study that has already confirmed that it can reduce hospitalization and death in people already infected.

Merck, whose stock is now up nearly 9%, is beating others to producing the first oral antiviral treatment for COVID-19. Its rivals, Pfizer and Swiss pharmaceutical Roche Holding AG, along with partner Atea Pharmaceuticals Inc, are conducting late-stage studies for their pills. Shares of Atea were up 19%.

Merck, which halted its own COVID-19 vaccine development, had its shares decreased roughly 4% for the year through Thursday before turning positive for 2021 on Friday, which indicates that their Research and Development is not only alive and well, but potentially looking at a multi-billion dollar opportunity.