 GlaxoSmithKline GSK, -0.60 GSK, 0.83 and partner Vir Biotechnology VIR, 1.96 said Tuesday that the U.S. government will buy 600,000 doses of sotrovimab, an investigational monoclonal antibody for early COVID-19 treatment. The extra doses will be delivered in the first quarter of 2022 to the U.S., which has an option to purchase more in the second quarter. 