Mask mandates help, but COVID-19 infection rates are driven by many factors

By Geoff Norcross (OPB)
Dec. 10, 2021 8:38 p.m.

Oregon’s infection rate remains stubbornly high, even with one of the toughest mask mandates in the country.

Oregon health leaders have taken a harder line on indoor mask-wearing than many other states. Masks will be required in indoor public spaces in Oregon for the foreseeable future.


OPB listener Stephanie wants to know, “Why has Oregon case rate numbers remained substantial or high, even with the mask mandate?”

Dr. Kim Repp, the chief epidemiologist with the Washington County Public Health division, says the mandate doesn’t always translate to good practices.

“I don’t know how many times you have seen somebody walking around with a mask below their nose,” says Repp. “It’s not a perfect thing, right?”

Repp is also skeptical about more lax states that publish lower infection rates.

She says, “If you look at Florida and Texas, you can see that their COVID incidence rates are lower than Oregon. But I would ask the question, are they testing?”

Repp spoke with OPB Morning Edition host Geoff Norcross. Some highlights from their conversation:

Dr. Kim Repp is the chief epidemiologist for the Washington County Public Health Division.

Dr. Kim Repp is the chief epidemiologist for the Washington County Public Health Division.

WCPHD / Courtesy Kim Repp

Geoff Norcross: “I want to check (Stephanie’s) facts first. Oregon case rates: have they been ‘substantial’ or ‘high’ compared to other states?”

Kim Repp: “It’s not in comparison to other states, it’s absolute. So the CDC basically assigns a risk level to not only every state but every county. And Stephanie is absolutely correct in saying that the state of Oregon, with the exception of Wheeler County, has been at substantial or high for quite a while. And we have, if not the strictest mask mandate, one of the most strict mask mandates in the country.”

Norcross: “Many other states have much more lax rules on masking, and they have high infection rates, too. Can you actually draw a line between those two things?”

Repp: “It’s not a one-to-one relationship between wearing a mask and infection rates. The lower case rates in some states may be due to lower testing. And mask mandates only work if people do them.

“ does help. The CDC did publish a study showing the association between mask mandates and lower case rates within a state.”

Norcross: “Stephanie also wants to know where all the cases are coming from. Schools? Within household transmission? Restaurants? Theaters? Gyms?”

Repp: “When you are in a substantial level of risk for transmission, that means you have community-wide spread. We can’t say you got it at the restaurant, right? You could get it at the sporting event. You could get it from your family. There are a million different places. You could be exposed depending on your risk behaviors. So we cannot nail it down. We are way past trying to find out where people were exposed.”

Norcross: “What good is a masking strategy if the mandates and the rules are different from state to state?”

Repp: “This is not even a state-to-state issue. This is a global issue. As long as we have countries like South Africa that have 22% of the population with one vaccine, the virus is going to go there and we’re going to get (the omicron variant). Oregon could have a 100% vaccine (rate). There are breakthrough cases. One state or one county is not going to be able to protect themselves from absolutely everything. It’s a combination effort to really protect against COVID. It’s not just one thing.”

Click on audio player at the top of this story to hear the full conversation.

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