NEW YORK (NewsNation Now) — Nurse Sandra Lindsay, who became the first person in the U.S. to receive the COVID-19 vaccine, was given her second and final dose on Monday.

Lindsay, a New York City intensive care unit nurse, was inoculated at Long Island Jewish Medical Center in Queens, roughly three weeks after she received her first shot of the Pfizer-BioNTech vaccine.

“My message is still that of hope,” she said Monday. “The initial study was done using two doses of the vaccine. So I feel like I’ve completed the marathon, I’ve closed the loop. I know that we’re not out of the woods yet. We don’t have that herd immunity yet. But the burden feels definitely much lighter today.”

Lindsay, who treated some of the sickest coronavirus patients in the New York City borough and lost two of her family members to the virus, made history when she received the first dose on Dec. 14.

“The vaccine is safe, I haven’t had any side effects,” she said. “It’s our civil responsibility in a crisis to just band together and get through this. COVID-19 has stripped us of our lives, our livelihoods, and 2021 is our opportunity to reclaim that.”

The Pfizer-BioNTech vaccine won emergency-use approval from federal regulators on Dec. 11 after it was found to be 95% effective in preventing illness in a large clinical trial.

Health care workers and elderly residents of long-term care homes were first in line to get the inoculations of a two-dose regimen given about three weeks apart.

New Jersey Gov. Phil Murphy watches as frontline health care workers receive their second doses of the COVID-19 vaccine developed by Pfizer and German firm BioNTech on Monday, Jan. 4, 2021. (Photo provided by Gov. Phil Murphy via Twitter)

Now, many across the U.S. are beginning to receive their second dose.

New Jersey Gov. Phil Murphy visited University Hospital in Newark Monday to oversee frontline health care workers become the first in the state to be fully vaccinated.

In Connecticut, frontline health care workers at Hartford HealthCare also received their second doses Monday, NewsNation affiliate WTNH reported.

Those who received the second shot on Monday had their first doses of the Pfizer vaccine on Dec. 14.

The vaccine that Moderna developed with the National Institute of Allergy and Infectious Diseases was first administered on Dec. 21. It received emergency use authorization roughly a week after Pfizer.

Moderna’s vaccine also requires two shots.