Sunday is a historic day in the nation's fight against the coronavirus pandemic.
The first truck carrying a COVID-19 vaccine for widespread use in the United States pulled out of a Portage, Mich., manufacturing plant Sunday morning, with the shots that are critical to stopping the nation's coronavirus outbreak destined to reach locations in all 50 states a day later.
The loading process began Sunday morning. The first wave of deliveries will see 150 locations supplied with the Pfizer-BioNTech’s COVID-19 vaccine, and a further 450 sites will see supplies in the second shipment.
The vaccine is timed to arrive Monday morning so that health workers can receive the shot before administering it themselves.
Shipments of the Pfizer vaccine will set in motion the biggest vaccination effort in American history at a critical juncture of the pandemic that has killed 1.6 million and sickened 71 million worldwide.
The vaccine rollout comes with the support of Operation Warp Speed, a massive private and public partnership put together by the Trump administration.
President Trump, who had been pressuring the Food and Drug Administration to expedite approval, said finding a coronavirus vaccine would have taken "five years" if he weren't president.
"If I wasn't president? According to almost everybody, even the enemy, if I wasn't president, you wouldn't have a vaccine for five years," Trump told Fox News' Brian Kilmeade in an interview that aired Sunday. "OK, I push the FDA and companies and everybody else involved like nobody's ever been pushed before."
Initially, about 3 million doses were expected to be sent out, and the priority is health care workers and nursing home residents as infections, hospitalizations and deaths soar in the U.S. With numbers likely to get worse over the holidays, the vaccine is offering a bright spot in the fight against the pandemic that's killed nearly 300,000 Americans.
Federal officials say the first shipments of Pfizer’s vaccine will be staggered, arriving in 145 distribution centers Monday, with an additional 425 sites getting shipments Tuesday, and the remaining 66 on Wednesday. The vaccine, co-developed by German partner BioNTech, is being doled out based on each state's adult population.
Fox News' Peter Aitken and the Associated Press contributed to this report.