LOS ANGELES (CNS) — Health care workers at Ronald Reagan UCLA Medical Center began receiving COVID-19 vaccinations Wednesday as the effort to inoculate millions of people in the county accelerated.

Emergency physician Dr. Medell Briggs-Malonson was the first person at the Westwood hospital to be vaccinated. After receiving the Pfizer vaccination, she told urged everyone to get the shot when it becomes more widely available.

"As an emergency doctor, I have truly seen what COVID does to people," she said. "And even if it doesn't kill you, many people go on to have long-term effects of COVID, both with their brain, with their heart or with their lungs."

By the end of the day, all nine sites in the county equipped with the ultra-cold-storage facilities needed for the Pfizer medication are expected to have the vaccine, with the county expected to receive nearly 83,000 doses. The vaccines will then be farmed out to 83 acute-care hospitals countywide for administration to health care workers, who are at the top of the priority list to receive the shots.

The vaccine, which received federal approval over the weekend for immediate use, is said to be 95% effective at preventing the virus.

Officials at Cedars-Sinai Medical Center confirmed Tuesday that Pfizer's much-anticipated vaccine had arrived at the hospital.

"The arrival of the COVID-19 vaccine signifies a powerful and positive shift change for our community after months of fear, exhaustion and illness," said Dr. Jeff Smith, chief operating officer of Cedars-Sinai. "Until today, the vaccine was the missing tool in our ever-growing toolkit of treatments and prevention methods against the virus."

The medical center has the capacity to house more than 450,000 doses of the vaccine onsite in several ultra-cold freezers, and health care workers in Cedars-Sinai's intensive care units and emergency department were among the first to be offered vaccinations, which are voluntary, Smith said.

On Monday, Kaiser Permanente Los Angeles intensive-care unit nurse Helen Cordova received one of the first doses in the state. Her vaccination began a massive undertaking that will see Los Angeles County attempt to inoculate 6 million people in six months.

Four other Kaiser workers were also vaccinated Monday as cameras rolled. About 17,000 doses of the medication were received at Kaiser.

"We front-line workers have been working around the clock over the past nine months, sacrificing so much of what we do and love to take care of our patients," Kaiser emergency room nurse Kim Taylor said after receiving a dose. "We've been doing this while trying to take care of our own families and keep them safe. What I want you guys to know is that help is on the way. Today is just a first step. Soon more vaccines will be distributed to the front-line workers and our most vulnerable populations."

She stressed the safety of the vaccine, and said that while the vaccine is offering hope, "the best way you can support us nurses right now is to continue wearing a mask, maintain physical distance, stay home for the holidays and wash your hands.

"We can't win this fight alone," she said. "We need your help to keep our numbers down and to slow this spread of COVID-19."

Statewide, 327,600 doses of the Pfizer vaccine were expected to arrive this week, with another 393,900 doses from Pfizer next week. Pending federal approval of Moderna's vaccination, the state is expected to receive 672,600 doses of that vaccine by the end of the month. The state hopes to receive as many as 2.16 million total doses by the end of the year, Gov. Gavin Newsom said.

Health-care workers and residents and staff of skilled nursing facilities and long-term care facilities are all included in what is known as Phase 1A of the vaccination-distribution program, meaning they will receive the first doses. Newsom said that group includes about 3 million people statewide.

Phase 1B of the program will be "essential workers," a category estimated to include 8 million people, Newsom said. Exact guidelines of what constitutes an "essential worker" and which ones will have the highest priority for vaccines have not been finalized. The state's Community Vaccine Advisory Committee, made up of about 60 people from various groups and professional associations, is scheduled to meet at 3 p.m. Wednesday to discuss recommendations for prioritizing vaccines among essential workers.

The committee's meetings are streamed on YouTube and can be access via telephone. Information is available here.

Los Angeles County's initial allotment of Pfizer vaccine is expected to be 82,875 doses, a population-based percentage of the state allocation, according to county Public Health Director Barbara Ferrer.

Last week, Ferrer said the county hopes to receive its second allotment — roughly 250,000 doses of the Moderna vaccine, pending FDA approval — early next week. Much of that second dose allotment will be distributed directly skilled nursing facilities, allowing them to administer it right away instead of waiting for a federal distribution agreement with CVS and Walgreens to begin on roughly Dec. 28.

Long-term care facilities will still receive the vaccine through CVS and Walgreens.

The Moderna vaccine does not require the same ultra-cold storage as the Pfizer vaccine.

The county anticipates receiving another 150,000 doses of vaccine by the end of December, followed by weekly allotments of 250,000 beginning in January. The Moderna and Pfizer vaccines both require two doses, separated by about three weeks. With the county planning to vaccinate 6 million people in six months, that equates to 12 million doses of vaccine.

After the distribution of vaccines to health care workers, skilled nursing facilities and long-term care staff and residents is completed, followed by "essential workers," priority will then move to people at highest risk of severe illness from the virus, such as seniors or those with underlying health conditions.

Distribution to the general public will follow, but the timeline on when that will occur remains cloudy.

The county's chief science officer said last week the process will be done equitably based on health priorities, not on power or prominence.

"Equity is a fundamental principle here," Dr. Paul Simon said. "We want to make sure all people have access, and that those that are at greatest risk either because of higher risk of exposure, or greater risk of severe illness because of chronic health conditions or other factors have more immediate access to the vaccine."