The nation’s first COVID-19 vaccine will begin arriving in states Monday morning, U.S. officials said Saturday, after the government gave the final go-ahead to the shots needed to end an outbreak that has killed nearly 300,000 Americans.

Trucks will roll out Sunday morning as shipping companies UPS and FedEx begin delivering Pfizer’s vaccine to nearly 150 distribution centers across the states, said Army Gen. Gustave Perna of Operation Warp Speed, the Trump administration’s vaccine development program. An additional 450 or so facilities will get the vaccine between Tuesday and Wednesday.