The COVID-19 delta variant is spreading so fast that it will hit most of the state’s unvaccinated population before the six weeks needed to be fully immunized if they got the shots now.

“We are looking at a giant wave that is all taking place over the next four weeks,” said Peter Graven, a top data scientist at Oregon Health & Science University.

Graven presented a forecast Aug. 10 that up to 1,100 people with COVID-19 will need hospitalization by the time the current wave of infections peaks around Sept. 7.

Oregon hospitals are about 500 staffed beds short of being able to absorb that many patients at one time, Graven said. With about 1.2 million unvaccinated people in Oregon, the delta variant has a large target to hit.

Oregon on Aug. 10 reported 635 COVID-19 cases in state hospitals, setting a new record for the pandemic. The previous high was 584 people on Nov. 30, 2020. The current wave has already set new records for infected patients in Intensive Care Unit beds. On Aug. 10, there were 164.

About 90% of those currently hospitalized are unvaccinated, Graven said.

Gov. Kate Brown said she will have an announcement about “statewide indoor mask requirements” on Wednesday.

The governor gave every indication there will be a mask mandate for Oregon to blunt the COVID-19 spike.

“This new mask requirement will not last forever, but it is a measure that can save lives right now,” Brown said.

The speed of the delta variant has astounded health officials, who said each infected person infects eight other unvaccinated people. Previous versions of COVID-19 didn’t exceed a 1-to-3 infection ratio.

“Being vaccinated now is too late for this surge,” said Dr. Renee Edwards, chief medical officer of the Oregon Health & Science University.

Edwards said the delta variant makes unvaccinated people sicker than earlier waves of COVID-19. Doctors are seeing younger, sicker patients as many of the elderly were vaccinated when the delta variant arrived.

Many of the newly admitted to hospitals require more care for a longer time, stretching staff and causing less turnover of beds for patients still to come.

Brown announced Aug. 10 that all executive branch employees of the state must be vaccinated by Oct. 18. The mandate includes state agencies under the governor’s control.

Brown said she hoped the legislative, judicial and other state agencies will follow suit.

The United States has reported over 36 million cases, with epidemiologists estimating the true number at twice as many due to under-reporting and cases with milder symptoms.

Nationwide, there have been 618,108 deaths from COVID-19 since January 2020, according to the Johns Hopkins Coronavirus Resource Center. Worldwide, it has killed over 4.3 million.

While California and Washington have been among the nine states to require masks to be worn indoors, Brown has steadfastly stuck with a voluntary effort. Oregon had statewide mask mandates earlier in the pandemic, but OHA officials said community appeals for voluntary compliance would better reach people who had refused masks in the past.

The rapidly moving delta variant convinced Brown and OHA that a blunt directive was needed now, especially with what OHSU estimates are 1.2 million residents of the state who are still unvaccinated, including children under 11 for whom no inoculation has been approved

“Oregon is facing a spike in COVID-19 hospitalizations — consisting overwhelmingly of unvaccinated individuals — that is quickly exceeding the darkest days of our winter surge,” Brown said. “When our hospitals are full, there will be no room for additional patients needing care — whether for COVID-19, a heart attack or stroke, a car collision, or a variety of other emergency situations.”

Because the main vaccines used in Oregon, made by Pfizer and Moderna, require two shots a month apart and a two-week waiting period afterward to ensure full immunity, medical experts said it is already too late for the unvaccinated to rely only on shots. They need to stay at home and keep social distance efforts in place. Everyone should wear masks indoors to tamp down the spread, they said.

Brown’s planned announcement could mean the end of her policy since June 30 to let each of the state’s 36 counties monitor public health and for county commissioners to impose restrictions if needed.

The policy stayed in place in recent weeks despite increasing infection rates in counties with low vaccination numbers. OHSU officials said infections were swamping hospitals in Josephine and Jackson counties, while a country music concert in Pendleton fueled a spike in new infections.

Despite the spike in cases, the only county to impose mask requirements has been Multnomah County, where the infection rate last week was half of the state average.

Brown has sharpened her criticism of inaction by local officials in areas with spiraling COVID-19 caseloads, especially as patients in eastern and southwestern Oregon had to be transferred to hospitals in Portland, Salem, Bend and out of state. Brown on Aug. 9 confirmed reports from around the state that she had contacted local officials in areas with rising cases to ask what they planned to do to slow the spread.

“We have a finite number of staffed hospital beds in Oregon,” Brown said in a statement. “If local leaders continue not to act and their regional hospitals exceed their capacity, it will impact hospitals all across the state.”

OHSU has had to reject some requests for transfers in order to keep a minimum number of beds available for emergency needs, including the “normal” mix of heart attacks, traffic accidents and other medical issues requiring hospitalization.

Oregon has the lowest number of hospital beds per capita in the nation, according to a 2018 report from the Kaiser Family Foundation. Edwards, the medical director for OHSU, would only say the state has fewer than most states per person. Staffing hospitals and other health care has become a major issue during the pandemic.

OHA reported Monday that 9.5% of all COVID-19 tests were turning up positive. That’s nearly twice the 5% level OHA has said is the highest rate that keeps infections from growing out of control.

Only Grant, Lake and Sherman counties were under the 5% mark. Multnomah County, the state’s most populous county with 829,560 residents, was at 5.3%.

Nine counties showed positive test rates above 18%, with Morrow at 29.2%. Umatilla County was at 26.4%. Infection rates topped 18% in Crook, Douglas, Curry, Jackson, Josephine, Malheur and Union counties.

Despite an uptick this month, vaccination levels in Oregon have slowed to an average of under 6,000 shots per day. That’s down from a peak of 45,000 per day at some points in April.

Anti-vaccination measures have also hamstrung efforts in the state. The Kaiser Health Network, a health news agency, reported Aug. 10 that Oregon is one of seven states with some kind of law that slows or prohibits the ability of health officials or medical supervisors to require vaccination of workers.

Oregon legislature passed a law in 1989 that specifically barred employers from requiring medical and health workers to be vaccinated. Officials and state lawmakers have been debating over the wording of the original legislation and whether it extends to statewide orders by government officials in an emergency. Democratic lawmakers said they would introduce legislation in the 2022 session to remove the ban.