BOSTON (CBS) - Now that Pfizer's vaccine has been approved by the FDA for emergency use in the United States, millions of doses will be shipped nationwide to begin distribution immediately.

First on the list to receive the vaccine are health care workers treating COVID-19 patients, like Katie Murphy, an ICU nurse at Brigham and Women's Hospital in Boston.

"I will take it," she told WBZ. Murphy is also the President of the Massachusetts Nurse's Association and said union members are typically very vaccine-positive, with more than 90 percent getting a flu shot each year. She anticipates the COVID-19 vaccine will see similar numbers.

Read: Mass. Communities Remain Vigilant, Prepare For COVID-19 Vaccine

"You have to have a robust, healthy workforce to take care of these increasing number of patients and the patients being so sick," Murphy said.

In this second surge of COVID-19, Murphy and her colleagues statewide are seeing an influx of COVID-19 patients in the ICU. "There's a great deal of sadness," she said. "Sadness for our patients. Sadness that they're putting their families through this again."

Murphy is ready to be among the first to get the Pfizer vaccine but worries about her patients and their families, especially those with comorbidities. "You know, in a perfect world, I wish [the vaccine] could be distributed to everybody who is able to take it tomorrow," she said.

That won't be the case though. Massachusetts has a three-phase plan that starts with health care workers and ends with the general public receiving the vaccine. If all goes according to plan, distribution will take more than six months. So far, the U.S. has only secured enough doses of the Pfizer vaccine to vaccinate 50 million Americans, and is relying on other companies, like Moderna in Cambridge, to be approved by the FDA soon and distributed.

While Murphy is excited about the vaccine's promise for fighting the pandemic, she's worried about the unintended effects it may cause on the community. "I'm concerned that people are going to see the presence of the vaccine and it is going to cause them to relax the strict standards that need to be maintained," she explained. "We need to mask. We need to maintain physical distancing. Gatherings have to be kept to an absolute minimum."

She says this second wave of the pandemic is challenging for her nursing colleagues statewide. "I think people are going into this with our eyes wide open and worried," she said.

Despite that worry, she's ready to fight this pandemic moving forward. "We still believe this work is a privilege," she said.