Nov 10 (Reuters) - Merck & Co Inc (MRK.N) and partner Ridgeback Biotherapeutics said on Wednesday the Japanese government will pay about $1.2 billion for 1.6 million courses of their COVID-19 antiviral pill molnupiravir. Countries have rushed to sign deals to buy molnupiravir, since data last month showed that when given early in the illness the drug could halve the chances of dying or being hospitalized for those most at risk of developing severe COVID-19. read more Merck expects to make 10 million courses of treatment by the end of 2021, with at least 20 million courses to be produced in 2022. If it gets authorization, molnupiravir, would be the first oral antiviral medication for COVID-19. On Tuesday, the U.S. government said it would buy another $1 billion worth of molnupiravir. read more Reporting by Manas Mishra in Bengaluru; Editing by Shailesh Kuber