PORTLAND, Ore. — A new COVID-19 forecast for Oregon was scheduled to come out on Friday, but Oregon Health and Science University's lead forecaster is still working on some new details. He did say he expects COVID to keep spreading through July.
The pandemic has taken some unexpected turns in the past two years, so predicting what to expect in a coming month can be challenging. In fact, it has OHSU's Peter Graven working into the holiday weekend to get a complete handle on the outlook for July in Oregon.
The late additions Graven is considering are the Omicron subvariants BA.4 and BA.5, both of which have come on strong in Oregon after initially remaining in the background during prior weeks when BA.2 and BA.2.12.1 were driving most of the state's cases.
"We didn't really know exactly what the impact would be," he said Friday afternoon. "There was some speculation, and now I think we have a pretty good idea that indeed we will see some increase in infection rates."
In fact, health officials say the two slightly newer subvariants are now responsible for more than half of new cases in the state.
The increased spread has prompted the Centers for Disease Control to raise the COVID-19 transmission risk level to high in most Oregon counties, including Oregon’s most populated places.
The Oregon Health Authority's Dr. Paul Cieslak said he's not surprised by the CDC’s take.
"A lot of people are getting COVID and they are spreading it to some people who are being hospitalized by it, probably predominantly people who have not been vaccinated or who are at risk of severe disease despite vaccination because of underlying health conditions," he said.
The number of COVID-19 patients in Oregon hospitals spiked in the past week after previously hovering around 300 since late May. The latest daily count on Thursday put the number at 418.
Graven's forecasts in prior weeks had predicted a plateau in mid-June, with hospitalizations not rising much farther, but he said the BA.2.12.1 subvariant upset that prediction.
"That mostly just extended the time that we've had this higher infection rate, and I expect BA.4 and 5 to do something similar," he said.
But there's important context for the hospitalization number: experts say more than half are incidental cases, meaning people went to the hospital for something else and when tested, came up positive for the virus.
That tells health officials the rate of serious illness appears to be lower for the type of COVID cases generated by the newer omicron subvariants. Deaths are also way down compared to prior surges like Delta and the first Omicron wave.