SALEM — The Oregon ZIP codes with the highest rates of recent coronavirus spread are among the state’s least vaccinated, an analysis by The Oregonian has found, helping fuel a record-setting surge in cases that is filling hospitals like never before.

Sixteen Oregon ZIP codes with exceptionally high case rates accounted for nearly 20% of the state’s weekly coronavirus cases, according to state data for the week ending Wednesday, Aug. 11.

And those ZIP codes had one thing in common: exceedingly low vaccination rates.

The communities with the highest recent case rates are concentrated in Eastern and Southern Oregon, encompassing Irrigon, Boardman, Roseburg, Sutherlin, Pendleton, Grants Pass, Winston, Umatilla, Roseburg, Myrtle Creek, Baker City and Hermiston. They also extend to the coast, to Tillamook and Brookings, and to Cottage Grove outside of Eugene.

Those ZIP codes each had at least 25 new confirmed or presumed infections, with corresponding weekly rates of more than 50 cases per 10,000 residents.

The vaccination rates in those communities topped out at just 51% among all residents — and in one case remained as low as 30%.

That’s far below the statewide average of 59.4% among all residents.

The problems in those communities foreshadow what may come for other low-vaccination areas across the state yet to be ravaged by the highly contagious delta variant. Public health officials say this is now a pandemic of the unvaccinated, with about 80% of cases from July in people who haven’t been fully inoculated. Officials for months have been urging people to get vaccinated to protect against COVID-19, saying it’s the best way to prevent hospitalization and death.

The Oregonian provided the Oregon Health Authority with its list of communities with the highest recent case rates. Asked what message the agency had for people living specifically in those areas to keep safe, prevent severe illness and not strain hospital capacity, a spokesperson provided a written statement.

“Our thoughts go out to all who are battling this virus across the state,” Delia Hernández wrote, in part. “We all need to take actions now to slow the spread by wearing our masks in indoor public places and if we are eligible for vaccination, and not yet vaccinated, we need to make a plan to get vaccinated.”

The high case rates and low vaccination rates are particularly apparent in some communities, the analysis found.

Morrow County’s 97844 ZIP code for Irrigon, for example, had 43 cases for the week ending Aug. 11. With a population of only about 4,100, that equaled a case rate of 104 per 10,000 people — the highest in the state for ZIP codes with at least 25 new cases.

The vaccination rate there? Just 33%.

The two ZIP codes that account for Grants Pass, in Josephine County, by far and away led the state in total new cases — without accounting for population. After factoring in the number of residents, the areas were seventh and eighth highest for case rates, at about 70 per 10,000 people.

The corresponding vaccination rates in those Grants Pass ZIP codes: about 45% and 42%.

Compare that to the Portland metro area, where vaccination rates are higher and case rates are lower.

The 97233 ZIP code in east Portland and Gresham has historically been one of the hardest hit throughout the pandemic. Yet with almost 54% of the population now vaccinated, it reported a weekly case rate of only 17 per 10,000 residents — one third of what the highest-spread areas in Oregon recorded.

It’s unclear how long that recent success will hold. State officials have all but said the delta variant will find the unvaccinated.