The delta variant surge in Oregon: What you need to know

By Amelia Templeton (OPB)
July 28, 2021 12:57 a.m.

The more contagious delta variant of COVID-19 is spreading rapidly across the nation. In just a few short weeks it’s changed everything. On Tuesday, the Oregon Health Authority reported 1,032 new cases of COVID-19. The last time the state reported more than 1,000 new cases in a day was at the peak of the spring surge in April.

Some Oregon schools are now requiring masks this fall, and the CDC is recommending that people in most parts of the country wear face coverings indoors in public places. Late Tuesday, OHA went along with that, recommending that people wear face coverings in “all public indoor settings” in the state.


OPB answers your questions about this latest wave of COVID-19 and who is most at risk.

Why are scientists and public health experts so concerned about the delta variant?

It’s the most contagious form of COVID-19 we’ve encountered yet. Epidemiologists use a measure called the reproductive rate to describe how fast a virus can spread if people don’t take any measures to control it. For original COVID-19 that rate was about 2 or 3, meaning each person with the virus would infect 2 or 3 other people. The reproductive rate for the delta variant is about 6 or 7, meaning without control measures, each person infects 6 or 7 other people.

Both the original and the variant spread exponentially in populations without immunity, but the delta variant spreads much more quickly — and requires a higher vaccination rate to stop the spread.

The head of the Centers for Disease Control and Prevention, Rochelle Walensky, has called it one of the most infectious respiratory diseases she’s ever seen.

Who’s most at risk?

Everyone’s at some degree of risk, but the risk is just, so much higher for people who aren’t vaccinated. So let’s talk about the risk for unvaccinated people first.

In Oregon, that’s about 40% of all residents, or about 30% of adults?

Right. The first big group of unvaccinated people is children under 12. Shots aren’t approved for them yet.

Throughout the pandemic children have been by far the least likely to get severe COVID-19, or to be hospitalized or die. Most have only had mild infections.

One urgent question about the delta variant is if it makes children any sicker than the original strain. The scientists we spoke with say there isn’t much reliable data on that yet, though there should be soon.

Scientists are concerned about the prospect of the delta variant spreading when school is back in session, starting at the end of August.

And the state has responded to that by strongly advising local school districts to require masks this fall. What do we know about unvaccinated adults in Oregon?

There are a couple of different lenses you can use to talk about unvaccinated adults.


Let’s start with race and ethnicity.

The state has race and ethnicity data for about 85% of the people who’ve been vaccinated so far. It shows that people who are Hispanic, or Black, as well as members of Native American tribes are much less likely to be vaccinated.

Ebony Clarke, the director of Multnomah County Public Health department, said those communities are now doubly at risk from the delta variant.

“Because we are impacted by chronic diseases such as diabetes, high blood pressure, and those types of things put us more at risk of being gravely impacted by COVID-19,” Clarke said.

To encourage people to talk to their unvaccinated friends and family, Multnomah County is offering $50 gift cards to vaccinated people who accompany their unvaccinated friends or relatives to get their shot.

Who else is less likely to be vaccinated?

Younger people and Republicans. There’s a growing vaccination gap between Republican and Democratic-leaning counties. Nationally, there’s about a 12% difference in vaccination rates between counties that voted for Joe Biden and counties that went to Donald Trump, according to an analysis by the Kaiser Family Foundation.

Finally, OHA publishes the zip codes in Oregon that have the largest unvaccinated populations. That data shows that Medford, Grants Pass, Salem and parts of Clackamas County all have large unvaccinated populations that are at risk for delta variant outbreaks.

What are the risks from the delta variant for people who are vaccinated?

Vaccination is by far the best protection against severe infection and death from COVID-19; 97% of hospitalizations are among unvaccinated people, according to the CDC.

Now here are the caveats: Your protection is going to be the best if you’ve gotten two doses of a shot. A single dose of Pfizer or Moderna or the one-dose Johnnson & Johnson may not provide as much protection against the delta variant.

And as someone who is vaccinated, there’s still the risk that you get a mild infection but transmit the virus to someone in your family — like a child — who isn’t vaccinated. Now we’re seeing the CDC calling for people who are vaccinated to wear masks.

California and New York have announced vaccination requirements for public employees. Nationwide, hospitals like the Mayo Clinic are announcing mandates. Is there anything like that happening here in Oregon?

Not yet. Where we’re starting to see a consensus building nationally is around vaccine mandates for health care workers.

Oregon is unique - state law prohibits employers from requiring health workers to be vaccinated. So hospitals, clinics, nursing homes can’t do it.

The state hospital association says that law, passed 30 years ago, is misguided. They want OHA to adopt new rules allowing hospitals to choose whether to mandate vaccination for their staff.

When will this surge be over?

That depends in part on our collective behaviors, like getting more people vaccinated and wearing masks in indoor public places.

One key statewide forecast is predicting that hospitalizations from this wave will peak again in late September and then begin to fall.