When emergency-room nurse Michelle Schroder walked up to her chair, Tracy Lauzon was giddy.

Lauzon, 52, a director of trauma and stroke care at the Medical Center of Aurora, raised her arms in the air as she greeted Schroder, one of the health care workers for whom Lauzon stood prepared to give a COVID-19 vaccine shot.

“It’s been a long haul,” said Lauzon, adding that it feels good to be able to offer the vaccine to people after months of the pandemic stretching on.

Colorado received its first shipments of a vaccine for COVID-19 on Dec. 14, and health care centers in different parts of the state doled out shots to health care workers during that week.

Schroder, 48, a clinical nurse coordinator for Centennial Medical Plaza, smiled under her mask after Lauzon placed the bandage on her arm the afternoon of Dec. 16 at the Medical Center of Aurora, a hospital along Interstate 225. Schroder wasn’t expecting an mRNA vaccine so quickly — at first, she wasn’t aware it was an option for combating COVID-19.

Technology that uses mRNA — “messenger ribonucleic acid,” molecules that carry genetic code from DNA to help make protein in cells — has been used in efforts to battle cancer, Schroder referenced.

“When you look at controlling a pandemic, the first line is always a vaccine,” said Schroder, noting that mask-wearing and other precautions help as well. “I’m hopeful that getting some of the population vaccinated will mitigate disease spread.”

Like other emergency rooms, the ER at Centennial Medical Plaza has seen a decline in volume of patients amid the pandemic because people fear coming in contact with COVID-19. But in the past couple months, Schroder has seen the numbers pick back up, and she’s seeing more COVID-19 patients in the ER than she did in April. Centennial Medical Plaza is a campus of the Medical Center of Aurora.

“We’re still here for (the public) no matter what it is,” Schroder said. “We’re taking absolute precautions with visitor restrictions and PPE (personal protective equipment) so we can treat patients without fear of (them) catching something.”

She emphasized that “wearing masks and washing hands works,” adding that she’s worked throughout the pandemic and has not gotten sick with COVID-19.

Schroder wants the public “to hang in there,” she said. “Wearing masks, washing hands, staying home if they don’t need to be out. We can see the light at the end of the tunnel, but we’re not there yet.”

Schroder, who lives in Aurora, felt excited to be the among the first groups of Coloradans to be vaccinated. But she also felt a sense of duty.

“I also feel it’s my responsibility to help stop the spread,” Schroder said. “I’m seeing a lot of folks (in the ER). If I can help folks get back to their jobs and kids get back to school, I’m going to do it.

“Because it’s not just about me,” Schroder said. “It’s about my community.”