The first shipments of the Pfizer-BioNTech COVID-19 vaccine are arriving in all 50 states today after the Food and Drug Administration issued an emergency use authorization late Friday. The vaccine is being deployed as the U.S. tops 300,000 recorded deaths from COVID-19 today, with confirmed cases topping 16.2 million — by far the highest numbers in the world. The first shipment will cover some 3 million people. Healthcare workers will receive the first doses this week, followed by nursing home residents and staff. FDA Commissioner Stephen Hahn said Sunday he hoped the first doses would be administered today. He also denied reports he was threatened by President Trump Friday to approve the vaccine quickly, saying the authorization was based on “a thorough review of the science and data.”

Meanwhile, the coronavirus vaccine developed by Moderna is likely to be approved by the end of the week, according to Operation Warp Speed chief adviser Moncef Slaoui. The U.S. government purchased another 100 million doses of the Moderna vaccine last week, which the Trump administration said would ensure continuous vaccine delivery through the end of June 2021.