New York's first doses of Pfizer's vaccine are expected to arrive Monday morning.
Shipping began Sunday morning following the emergency use authorization from the FDA on Friday.
Government officials say UPS and FedEx are splitting shipping duties — their trucks are heading out from Michigan to nearly 150 distribution centers across the country.
Hundreds of other distribution centers will be getting vaccines Tuesday and Wednesday.
At-risk healthcare workers and nursing home residents and staff will be the first to get the shots.
The vaccine has been confirmed to be 95% effective, and the FDA has been insistent that despite the fast timeline of the vaccine getting approved, no corners were cut and all proper steps were taken to make sure it's safe.
They say studies on the vaccine will continue.
The FDA warns that anyone with prior allergic reactions to a vaccine should talk to their doctor first.
Health experts say there is not enough data yet on women who are pregnant or nursing. Testing on these groups is expected to be completed early in 2021.