SALEM — After weeks of explosive growth, the expansion of the coronavirus delta variant appears to be peaking.

The number of new COVID-19 cases requiring hospitalization, which skyrocketed in August, should start to flatten after Monday, Sept. 6, and will begin to decline in October or November, said Peter Graven, the leading data scientist at Oregon Health & Science University, Portland. Graven has been modeling expected coronavirus-related hospitalization numbers on a weekly basis since the beginning of the pandemic.

Yet the pandemic is far from over. The potential high point next week of hospitalized COVID-19 patients could reach a record setting 1,208.

Graven attributed the expected turnaround to more masks and more vaccines.

“We’re seeing evidence that people have changed their behavior to protect themselves and others,” he said, “and that will need to continue if we’re going to be able to free up space in our hospitals.”

August proved to be the third deadliest month in Oregon since the start of the pandemic.

Graven’s data show masking rates have ticked up to about 80% and Oregonians have refrained from gathering in indoor markets, grocery stores, bars and in large groups. In addition, more people appear to be getting vaccinated in response to the alarming surge in critically ill Oregonians.

“We still have lots of people getting sick,” he said. “There’s still a ton of transmission going on out there. For anyone who works in health care, the next month will continue to feel like crisis mode.”

There’s another development worrying Graven — the beginning of school. It remains to be seen whether teachers and students will be able to maintain a tight masking discipline all day, a necessity against the highly infectious delta variant.

So far, children under 12 are not eligible to take any of the vaccines.

“I am concerned about it,” Graven said. “There is pretty good evidence that we didn’t have outbreaks (in schools.) But this fall is different — it’s the normal full day.”