By , , DETROIT/LOS ANGELES/NEW YORK (Reuters) - U.S. distribution of Moderna Inc’s COVID-19 vaccine began on Saturday, with more than 3,700 sites due to start receiving and administering shots as soon as Monday, vastly widening the rollout started last week by Pfizer Inc.Amid record coronavirus infections and deaths, Moderna has already moved vaccine supplies from its manufacturing plants to warehouses operated by distributor McKesson Corp.Workers on Saturday were packing vaccines into containers and loading them on trucks, U.S. Army General Gustave Perna said during a news conference....…By , , DETROIT/LOS ANGELES/NEW YORK (Reuters) - U.S. distribution of Moderna Inc’s COVID-19 vaccine began on Saturday, with more than 3,700 sites due to start receiving and administering shots as soon as Monday, vastly widening the rollout started last week by Pfizer Inc.Amid record coronavirus infections and deaths, Moderna has already moved vaccine supplies from its manufacturing plants to warehouses operated by distributor McKesson Corp.Workers on Saturday were packing vaccines into containers and loading them on trucks, U.S. Army General Gustave Perna said during a news conference....WW…