The loading process for the first shipment of Pfizer/BioNTech’s coronavirus vaccine began on Sunday morning at a facility in Kalamazoo, Michigan, with plans for the shipment to go to all 50 states.

The landmark moment in the pandemic comes after the vaccine received the FDA’s emergency use authorization, and in the coming days, the vaccines will be sent out to hundreds of facilities across the United States.

“We expect 145 sites across all the states to receive the vaccine on Monday, another 425 sites on Tuesday, and the final 66 sites on Wednesday, which will complete the initial delivery of the Pfizer orders for the vaccine,” said Gen. Gustave Perna, chief operating officer of the federal government’s vaccine initiative Operation Warp Speed.