US Researchers Say COVID-19 Antiviral Shows PromisePharmaceutical giant Merck and an American laboratory announced progress Saturday in the design of an oral drug against COVID-19. Their antiviral has shown positive effects in reducing the viral load in current tests. "Knowing that there is an unmet need for antiviral therapy for SARS-CoV-2, we are encouraged by these preliminary results," Wendy Painter, chief drug officer at Ridgeback Biotherapeutics, said in a statement. Merck interrupted its work on two potential COVID-19 vaccines at the end of January but continues its research on two treatments against the disease, including molnupiravir, developed with the American company Ridgeback Bio. The drug significantly reduced the viral load in patients after five days of treatment, the company said Saturday in a meeting with infectious-disease specialists. Phase 2a of the test — the trials have three phases before possible marketing — was carried out on 202 out-of-hospital patients who had COVID-19 with symptoms. There was no alert in terms of safety, and "of the four serious incidents reported, none was considered in connection with the drug studied," the laboratory said. Influenza drugs like oseltamivir (Tamiflu) and zanamivir (Relenza) are sometimes prescribed for seasonal flu, but research is struggling to find an antiviral for COVID-19. The results of this study, "namely a more rapid decrease in the viral load in individuals with COVID-19 in the initial phase and who have received molnupiravir, are promising," assured William Fischer, one of the directors of the study and professor of medicine at the University of North Carolina. "If they are reinforced by additional studies, they could have important consequences in terms of public health, as the virus continues to spread and evolve in the world." Merck is also working on a treatment called MK-711. The first results of clinical trials show a reduction of more than 50% in the risk of death or respiratory failure in hospitalized patients with moderate to severe forms of COVID-19, the group said at the end of January.