The new program, announced on Thursday by the Department of Health and Human Services, will speed up the clinical trials of a few promising drug candidates. If all goes well, some of those first pills could be ready by the end of the year. The Antiviral Program for Pandemics will also support research on entirely new drugs — not just for the coronavirus, but for viruses that could cause future pandemics. A number of other viruses, including influenza, H.I.V. and hepatitis C, can be treated with a simple pill. But despite more than a year of research, no such pill exists to treat someone with a coronavirus infection before it wreaks havoc. Operation Warp Speed, the Trump administration’s program for accelerating Covid-19 research, invested far more money in the development of vaccines than of treatments, a gap that the new program will try to fill. Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases and a key backer of the program, said he looked forward to a time when Covid-19 patients could pick up antiviral pills from a pharmacy as soon as they tested positive for the coronavirus or develop Covid-19 symptoms.