Oregon’s COVID-19 omicron hospitalization peak won’t be nearly as bad as forecasters predicted a week ago but could still overwhelm the health care system within weeks with about as many people needing hospital beds as did during the delta wave.

Oregon Health & Science University revised its omicron surge projections Thursday, down from about 2,400 people hospitalized at the peak of the upcoming surge to about 1,200, provided Oregonians take steps to prevent the spread of infections.

The peak, which is expected to hit in early February, could exceed 1,700 if Oregonians’ behavior doesn’t change, though it always has in the past when infections have started to climb, OHSU data analyst Peter Graven said.

But while the downward revision could be heartening, the currently predicted wave of hospitalizations could still rival or exceed Oregon’s peak in early September.

“The risk of overwhelming hospital systems is real,” Graven said. “We’re seeing a dire situation.”

Graven said he incorporated new, more accurate data from countries fully in the throes of their omicron surges in his COVID-19 forecasting model, allowing him to make more accurate predictions for what will happen in Oregon.

The numbers could be revised down again next week, when Graven hopes to produce a forecast with yet more accurate data. The key variable driving the uncertainty is how likely an omicron infection is to land a vaccinated person in the hospital.

For his latest run at the data, Graven lowered omicron’s hospitalization rate, but upped the variant’s “immune escape,” or the rate at which the virus evades the defenses of immune systems that had already been exposed to the virus. He also upped his estimate of how many people, on average, will get boosters every day. The result showed a dramatically lower peak hospitalization rate.

The peak could end up even lower if Oregon’s efforts to get people boosted are particularly successful, according to Graven’s modeling.

Omicron-driven cases should start climbing now, Graven said, and hospitalizations will soon follow.

“One way we’re going to know is we’re going to see a lot more breakthrough cases,” Graven said.

Oregon Health Authority experts have said the variant is likely already the dominant one in Oregon, though there is such a lag in sequencing data that the state does not know for sure.

COVID-19 cases among vaccinated people have consistently accounted for about 30% of known infections since early November. With omicron, people who have had a regular course of two doses of the vaccine appear to be just as likely to get infected as those who haven’t been vaccinated, research shows.

The omicron variant appears to cause milder illness, but spreads so easily and so fast that the sheer volume of sick people is expected to send hundreds to the hospital. Having two shots of the vaccine helps prevent serious illness but does not always do so. Boosters are considered the best available option for those who are eligible.

The Oregon Health Authority and Gov. Kate Brown last week put the state on notice after Graven’s previous forecast came out, urging 1 million more Oregonians to get a booster shot.

The health authority announced Thursday it will open four clinics, in addition to the six already in service. The agency has asked providers to double or triple how many doses they administer each week. The health authority has also hired 60 additional vaccinators, who will be sent to help at medical facilities around the state, spokesperson Rudy Owens said.

But the health authority plans to shut down all six of its high-volume clinics for some portion of the holidays, citing health care workers’ exhaustion.

“We want to ensure they get a much deserved opportunity to rest and spend time with their friends and families,” Owens said in an email.

And, per the OHA, the state’s clinics aren’t the core engine behind the statewide vaccination effort. The high-volume sites will administer about 10% of the shots to be provided statewide, Owens said.

“We believe it will be more efficient and productive to scale up existing providers like clinics and hospitals where we can,” Owens said.

Deschutes County Fairgrounds, 3800 SE Airport Way, Redmond operates a drive-through clinic.

• Open every day, 12 to 7 p.m.
• Closed Dec. 23 through Jan. 3

Polk County, Spirit Mountain Casino, 27100 SW Salmon River Highway, Grand Ronde, starting Jan. 15.

• Open Monday through Saturday, 12 p.m.- 7 p.m.
• Sunday from 11 a.m.- 4 p.m.

Coos County, Pony Village Mall, 1611 Virginia Ave., North Bend, starting Jan 8.

• Open daily (including weekends) from 10 a.m.- 5 p.m.

Jackson County Expo Center, 1 Peninger St., Central Point

• Open every Monday through Thursday, 12 to 7 p.m.
• Sundays, 11 a.m. to 4 p.m.
• Sundays in December, family fun clinic, 11 a.m. to 4 p.m.
• Closed every Friday and Saturday
• Closed Dec. 23 through Dec. 26 and Dec. 31 through Jan. 1

Lane County, PeaceHealth Riverbend Annex, 123 International Way, Springfield

• Open every Tuesday through Saturday, 12 to 7 p.m.
• Sundays, 11 a.m. to 4 p.m.
• Closed every Monday (including Jan. 3)
• Closed Dec. 23 through Dec. 27

Lane County, Florence Events Center, 715 Quince St., Florence, starting Dec. 31.

• Open daily Monday through Saturday from 12 p.m.- 7 p.m.
• Sundays from 11 a.m.- 4 p.m.
• This clinic will be closed on Tuesday, Jan.18.

Marion County, Oregon Health Authority Warehouse, 3455 Aumsville Hwy SE, Salem

• Open every Monday through Saturday, 12 to 7 p.m.
• Sundays, 11 a.m. to 4 p.m.
• Closed Dec. 24 and Dec. 25

Douglas County, Roseburg Public Library, 1409 NE Diamond Rd., Roseburg, starting Jan.4.

• Open daily (including weekends), 10 a.m.- 5 p.m.

Multnomah County, former Kmart building, 440 NW Burnside Rd., Gresham

• Open every Monday through Saturday, 12 to 7 p.m.
• Sundays, 11 a.m. to 4 p.m.
• Closed Dec. 24 and Dec. 25
• Site closing Dec. 30 and relocating to Multnomah Greyhound Park. Opening date to be determined.

Washington County, Tektronix, 14200 SW Karl Braun Drive, Building 58, Beaverton

• Open every Monday through Saturday, 12 to 7 p.m.
• Sundays, 11 a.m. to 4 p.m.
• Closed Dec. 23 through Dec. 26

— Fedor Zarkhin

503-294-7674; fzarkhin@oregonian.com