New York on Monday inoculated its first healthcare worker with the Pfizer/BioNTech Covid-19 vaccine, marking a pivotal turn in the US effort to control the deadly virus.
Sandra Lindsay, an intensive care unit nurse, was given the vaccine at the Long Island Jewish Medical Centre in Queens, an early epicentre of the country's Covid-19 outbreak.
Ms Lindsay received applause on a livestream with New York Governor Andrew Cuomo.
"It didn't feel any different from taking any other vaccine," she said. "I feel hopeful today, relieved. I feel like healing is coming. I hope this marks the beginning of the end of a very painful time in our history. I want to instil public confidence that the vaccine is safe."
Minutes after Ms Lindsay's injection, President Donald Trump sent a tweet: "First Vaccine Adminstered. Congratulations USA! Congratulations WORLD!"
Northwell Health, the largest health system in New York, operates some of the select hospitals in the United States that were administering the country's first inoculations of the Pfizer/BioNTech Covid-19 vaccine outside trials on Monday.
The vaccine, developed by Pfizer and its German partner BioNTech, won emergency-use approval from federal regulators on Friday after it was found to be 95 per cent effective in preventing illness in a large clinical trial.
The first 2.9 million doses began to be shipped to distribution centres around the country on Sunday, just 11 months after the United States documented its first Covid-19 infections.
As of Monday, the United States had registered 16,286,343 cases and 299,489 deaths from the virus.
Hospitals in Texas, Utah and Minnesota said they also anticipated receiving their first doses of the vaccine at select hospitals on Monday, to be administered right away.
Shipments
The first US shipments of coronavirus vaccine departed from Pfizer's facility in Kalamazoo, Michigan on Sunday, packed into trucks with dry-ice to maintain the necessary sub-Arctic temperatures.
Workers clapped and whistled as the first boxes were loaded onto trucks at the factory.
The shipments were then were transported to UPS and FedEx planes waiting at air fields in Lansing and Grand Rapids, kicking off a national immunisation endeavour of unprecedented complexity.
The jets delivered the shipments to UPS and FedEx cargo hubs in Louisville and Memphis, respectively, from where they were loaded onto planes and trucks to be distributed to the first 145 of 636 vaccine-staging areas across the country. Second and third waves of vaccine shipments were due to go out to the remaining sites on Tuesday and Wednesday.
"This is the most difficult vaccine roll-out in history. There will be hiccups undoubtedly, but we've done everything from a federal level and working with partners to make it go as smoothly as possible. Please be patient with us," Surgeon General Jerome Adams told Fox News on Monday, adding that he would get the shot as soon as he can.
Healthcare workers and elderly residents of long-term care homes will be first in line to get the inoculations of a two-dose regimen given about three weeks apart.