Much has improved since then, and supply of the new drugs is likely to be extremely limited initially. Merck, for instance, is expected to supply enough of its drug to treat slightly more than 3 million Americans before February. Still, the new antivirals could put America’s still shaky testing infrastructure to the test, experts said. And officials will need to ensure that quick, affordable virus tests are available in the communities that have been especially hard hit by COVID. “People have to want to get tested, and we have to be able to get tests to people quickly,” said Dr. David Boulware, an infectious disease specialist at the University of Minnesota. “Can that happen?” Currently, the most effective treatments available for COVID in the U.S. are monoclonal antibody drugs, which bind to the virus and stop it from infecting cells. But these treatments are typically administered intravenously by health care workers. This can pose logistical challenges both for hospitals, many of which are overburdened and short-staffed, and for patients, who may not be able to get to clinics or infusion sites. The new antivirals are different. “You could potentially pick up your prescription and go home,” said Dr. Michelle Barron, the senior medical director of infection prevention and control for UCHealth, a health care system in Colorado.