EVERETT — About 50,000 people across Snohomish County are to become eligible for COVID-19 vaccines as the state advances Wednesday in its vaccine rollout.

Phase 1B2 opens eligibility to grocery store clerks, agricultural workers, food processors, bus drivers and other staff at congregate settings, as well as women 16 or older who are pregnant, and anyone 16 or older with a disability that puts them at high risk.

In addition to those included in earlier phases, the total number of county residents eligible for a shot is now 150,000, but supply is still limited.

“We continue to make progress every day in the county,” Snohomish Health District county health officer Dr. Chris Spitters said during a Tuesday media briefing. “But unfortunately, our allocation numbers are not keeping pace with our ambition and our capacity to administer the doses.”

With 150,000 people eligible, demand for first-dose appointments is high and will likely remain that way for weeks.

But as more people get vaccinated, and manufacturers ramp up production, the process should become less frustrating, Spitters said.

If you’re unsure about your place in line for the vaccine, visit www.findyourphasewa.org, or reach the county’s vaccine call center at 425-339-5278.

This week, about 26,000 vaccine doses are coming to the county — with 15,000 going to mass vaccination sites and medical providers, and the remaining 11,000 headed for pharmacies.

Of the total, a majority of the vaccine is reserved for first shots, whereas previous shipments focused on getting people their final dose.

In the past week, the county has hosted multiple second-shot-only clinics. But demand has slowed.

One reason is about 15% of people visiting the county’s mass vaccination sites don’t return for their second shot, Spitters said.

Some likely went elsewhere to get their final dose. But others likely opted against completing the vaccine cycle.

“Not everyone takes it all the way,” Spitters said. “We do the best we can, but if someone’s not coming back, we’re not going to persist too long on that.”

Countywide, nearly 70,000 people are fully vaccinated, while another 126,000 have received the first of two doses.

Meanwhile, the county’s key COVID metrics continue to trend in the right direction.

The rolling case rate dropped to 71 new cases per 100,000 people over 14 days — the lowest it’s been since early October.

“That’s great news,” Spitters said. “The lower we can get this incidence, the longer leeway we have to get vaccination out before the next wave might come.”

Keeping case counts low also makes it more difficult for variants of the virus to spread, Spitters said.

Hospitalizations and deaths from the virus have also continued to decline.

Joey Thompson: 425-339-3449; jthompson@heraldnet.com. Twitter: @byjoeythompson.

County mass vaccination site schedule

• Angel of the Winds Arena in Everett: Single shot Johnson & Johnson appointments, Tuesday through Thursday.

• Boeing Activity Center in Everett: First dose Moderna shots, Tuesday through Friday.

• Edmonds College: First dose Moderna shots on Tuesday, Wednesday, Friday and Saturday.

• Evergreen State Fairgrounds in Monroe: First and second doses of Moderna, Tuesday through Saturday.

• Arlington Municipal Airport: Closed for the week.