The first shipment of Pfizer/BioNTech reached Washington Monday, and doses will be adminstered beginning this week.

Vaccines were unboxed at the University of Washington Medical Center, and the first distribution of the week’s expected 62,400 doses will be distributed to 17 sites across 13 counties statewide. The Food and Drug Administration approved an Emergency Use Authorization for the vaccine on Dec. 12.

The first round of vaccines will go to health care workers in high-risk situations, such as those who care for patients with COVID-19, along with the residents and staff of long-term care facilities.

“”The vaccine is a sign of hope that the pandemic is something we can overcome,” Secretary of Health John Wiesman said. “We still have a long way to go to beat COVID-19, but this is the tool that will start saving lives immediately.”

A second vaccine, from pharmaceutical company Moderna, will have its application for Emergency Use Authorization reviewed this week, potentially bringing more vaccines to the state before the end of the year.

Washington is expected to receive approximately 222,000 doses of the Pfizer vaccine by Dec. 31 — with regular weekly shipments beginning in January — and expects 183,800 doses of the Moderna vaccine, if approved, in the same timeframe.

The Department of Health estimates that 500,000 Washington residents will be eligible for the vaccine in phase 1a. The Pfizer/BioNTech vaccine is given in two doses, 21 days apart; clinical trial data shows it is 95 percent effective at preventing COVID infection beginning seven days after the second dose.

“We believe that if everything goes according to plan, we’ll have most people in Washington vaccinated by mid-summer,” said Michele Roberts, one of the leaders of the DOH vaccine planning group. “The rapid development of these vaccines, with such a high rate of efficacy, is a historic achievement, and will help us defeat COVID-19.”