The U.S. government has agreed to pay $1 billion to Janssen Pharmaceutical Companies of Johnson & Johnson for 100 million doses of its experimental COVID-19 vaccine.

The Department of Health and Human Services and Department of Defense announced the agreement Wednesday. The vaccine doses could either be used in clinical trials or, if authorized as an effective preventive by the Food and Drug Administration, distributed as part of a COVID-19 vaccination campaign, HHS said in a statement. The deal increases the likelihood that the United States will have at least one safe, effective vaccine by 2021, HHS Secretary Alex Azar said.

In other COVID-19 drug news:

NIH Director Francis Collins

Four existing drugs, paired with remdesivir, have COVID-19 treatment potential:  A National Institutes of Health-funded study has found that four existing drugs, each when coupled with remdesivir, may help block COVID-19 infections, according to NIH Director Francis Collins, M.D., Ph.D.

“Some of the most promising drugs on the list reduced the number of SARS-CoV-2 infected cells by 65% to 85%,” he said.

The most potent of the four is apilimod, a drug that has been tested for treating autoimmune conditions and now is being evaluated for its ability to prevent the progression of COVID-19. Another is clofazimine, a 70-year old FDA-approved leprosy drug. The agency also has begun testing remdesivir in concert with a multiple sclerosis drug, interferon beta-1a, it announced Thursday. All together, the NIH has identified 21 existing drugs that have potential for evaluation as COVID-19 treatments. 

NIH begins trials of COVID-19 antibody treatments: Two randomized controlled clinical trials are underway to test multiple monoclonal antibody treatments for use against COVID-19 in both inpatients and outpatients, according to Inside Health Policy. Monoclonal antibodies can be used to slow disease progression. They’ve been touted as a possible preventive and a treatment by National Institute of Allergy and Infectious Diseases Director Anthony Fauci, M.D.