"Oh here we go!" In Denver, a box packed with vials of ​the Pfizer/BioNTech vaccine arrives at the Colorado State Lab. It's the first installment of the COVID-19 drug that will arrive by the truckload in the coming weeks. Health care workers who've been on the front lines of the pandemic are the first recipients.

"The last nine months feel like nine years, or 90 years. It just feels like an eternity for those folks who have to go in every day, risk getting it, many of them have contracted it," said Colorado Governor Jared Polis.

Kevin Londrigan, a respiratory therapist, was chosen to get Colorado's very first vaccine shot.

"We're right up front with these patients, we get the worst of the worst and we're in their rooms probably 10 hours out of a 12-hour day," Kevin Londrigan said. 

Londrigan works with COVID-19 patients 95 percent of the time in his job and calls this year emotionally exhausting. The vaccine represents a light at the end of the tunnel for him and many, many others.

Dr. Michelle Barron, UC Health Infection Prevention Senior Director said, "It's extraordinarily exciting and anxiety-laden at the same time."

UC Health's Dr. Michelle Barron says the unknowns about the vaccine rollout, the things she and her colleagues haven't prepared for, are what worry her the most. Conquering the pandemic, she says, is like finishing a marathon.

"You're so close and you can see it and everybody's cheering and is excited and trying to egg you on, but can you get there and we will. Not without some pain potentially,”​Dr. Michelle Baron said. 

"I'm glad the vaccine has finally come out. I think it's safe, it's had the research, it's had the clinical trials. I feel safer coming home to my family at night," Kevin Londrigan said.

Londrigan said being picked was like winning a radio station contest. With vials of the drug, which contain five separate doses each, lined up and ready, it was time for nurse Christy Ruffell to do her thing.

"I do feel very humble to be picked to do this," Ruffell said, "Hi Kevin, my name is Christy and I'm going to be your nurse."

133 Coloradans were administered the vaccine on Day One. With ​the Moderna vaccine just behind Pfizer in the ​approval pipeline, states like Colorado will have to juggle who gets the drugs and where they're sent.

Scott Bookman, Colorado Health Department Incident Commander said, "we got a balance to strike here. People want to move fast, we have to be careful. This is just the beginning of a very long road."

One quarter of Colorado's COVID-19 deaths have come in the past month. Thousands of cases continue to be reported every day.

"We want to be excited, we want to have optimism but it needs to be tempered with the fact, as you say, that rates are still very high," Dr. Michelle Barron said.

Still there's new hope in the fight against the virus. "What this means, this triumph of modern science, is that an end to the pandemic is in sight," Colorado Governor Jared Polis said.