Sandra Lindsay, a critical care nurse at Long Island Jewish Medical Center in New York, on Dec. 14 was the first American to receive a new COVID-19 vaccine.
"It didn’t feel any different from taking any other vaccine," she said.
"I would like to thank all the front-line workers, all my colleagues who've been willing to fight this pandemic, all over the world. I feel hopeful today, relieved. I hope this marks the beginning of the end of a very painful time in our history."
Lindsay said she wanted to instill public confidence in the safety of the vaccine.
Lindsay's vaccination was shown during a press conference held by New York Gov. Andrew Cuomo, a Democrat. Dr. Michelle Chester of Northwell Health administered the shot.
"Everything worked perfectly," she said.
Northwell Health planned to vaccinate at least two other workers on Dec. 14.
"This is what everybody has been waiting for," Michael Dowling, president and CEO of Northwell Health, said at the briefing.
Cuomo said scientists estimate at least 75 percent of Americans need to get the vaccine in order for it to be effective; he called on every American to "do their part."
"It's going to take months before the vaccine hits critical mass. So, this is the light at the end of the tunnel but it's a long tunnel and we need people to continue to be, do the right thing and the smart thing all through the holiday season," he added.
President Donald Trump, whose administration focused on speeding up the development of both COVID-19 vaccines and therapeutics, celebrated the moment. "First Vaccine Administered. Congratulations USA! Congratulations WORLD!" he wrote in a tweet.
In Ohio, health professionals administered vaccines to five people simultaneously at 10:47 a.m. Those in the room applauded after the injections were given.
Approximately 2.9 million doses were set to be delivered to states by the end of Dec. 16, marking the first tranche of 40 million injections projected to be given this month.
The vaccine is administered across two doses spaced three weeks apart.
The Food and Drug Administration on Dec. 11 approved emergency use of the vaccine, which is made by Pfizer and BioNTech.
Drug regulators are meeting this week to consider approval of a different vaccine made by Moderna.