The latest forecast for omicron in Oregon

Oregon is seeing a surge in COVID-19 cases due to the highly contagious omicron variant. The latest projections from Oregon Health and Science University data scientist Peter Graven are less dramatic than the modeling he shared in mid-December, but he still says omicron hospitalizations will exceed those from the delta surge. We talk with Graven about his modeling and what he’s learned from looking at data from omicron infections on the east coast and in Europe, and hear from Dawn Nolt, a professor of pediatrics and infectious diseases at OHSU.

The following transcript was created by a computer and edited by a volunteer.

Dave Miller:  1,652. That’s the latest projection for the number of Oregonians with COVID who could be hospitalized at the peak of the current omicron surge. It is well above the delta peak this past September. Peter Graven is the man behind this projection and many others for the last almost two years of this pandemic. He is the Director of the Office of Advanced Analytics and the lead data scientist at OHSU. He joins us now once again along with Dawn Nolt, a pediatrician at OHSU who specializes in infectious diseases. Welcome back to both of you.

Dawn Nolt:  Thanks for having us.

Peter Graven:  It’s good to be back, hopefully for the last time.

Miller:  Yeah, let’s make that happen. Peter, you appeared at a press conference with Oregon Governor Kate Brown on December 17th with some really dramatic peak hospitalization numbers you were modeling at the time. Then you revised them significantly downwards and then they came up a bit in your most recent forecast. I don’t remember this much variation from week to week before. What are the challenges right now from a modeler’s perspective in terms of omicron?

Graven:  The key issue is that for a while there we were really narrowing down the number of people who are susceptible. So it becomes pretty easy to figure out who could get infected, who could get hospitalized. What happened with omicron is it opened back up the entire state basically to potentially getting infected. And so when you’re talking about 4.3 million people, how many of them might end up in the hospital one day, it turns out it fluctuates quite a bit until you get that parameter and are able to model in other places more accurately. So I did see it move around as well. I think we’re getting closer to the truth. Unfortunately the news is still bad because we’re seeing those spikes in other states and they’re getting pretty close to home.

Miller:  Is it still the case that you’re talking about 4.3 million people meaning everybody is potentially susceptible. But isn’t it still the case that even with omicron, people who are fully vaccinated or even vaccinated and boosted, it’s still very unlikely that they’re going to be hospitalized because of omicron?

Graven:  That is true. The vaccination is providing pretty much the same amount of protection against hospitalization and in the ICU and on a ventilator and dying as before. But it’s not providing the same protection against infection. And so we really are seeing that your vaccination isn’t helping a whole lot, meaning yes, a lot more people are getting infected. And therefore the probability that you get hospitalized is being multiplied by a ton more people than it was before.

Miller:  Why is that? I mean because if you’re saying even if it’s very unlikely you’re going to be hospitalized, if tons of people who are vaccinated are getting sick, even if it’s a very small percentage, some number of them might end up hospitalized. Is that what you’re saying?

Graven:  Exactly.

Miller:  When do you expect cases to peak? And when are hospitalizations expected to peak?

Graven:  I think infections and cases will probably peak in the next two weeks or so. You know, I can’t pick the day itself. Then usually the hospitalizations peak about 10 days after that. So that takes us to the end of January. So, the month of January is not looking good. Right now we are right at the beginning of seeing that nearly vertical line occur that we’ve seen in many other states.

Miller:  What goes through your mind as a doctor at the hospital when you look at the most recent projections coming out of Peter Grayson’s office?

Nolt:  Well, as a practicing clinician, I think of the healthcare workers I work with, and also our hospital’s capacity to take care of people. Right now our healthcare workers are really stretched and burnt out. And they themselves are also getting infected because if there’s so much transmission out there, those cases are going to include some of our health care workers. And even though they’re vaccinated and they’re boosted and they’re wearing all the right personal protective equipment, if they get infected that means they’re out and not able to work in our hospital for at least five days. So that really crunches our ability to take care of people.

And then as you know, and this has been a point that we’ve been stressing ever since delta and even in the past two years, our hospitals are really overcrowded. And looking at Peter’s data with cases going up and some proportion of those needing to be hospitalized, we are looking at a pretty rough January.

Miller:  So you’re already seeing healthcare workers who can’t come into work right now, nurses or doctors or plenty of other people because of omicron infections?

Nolt:  Yes, we are. We presume it’s omicron right?  We can’t genotype everyone but since that’s the prevailing circulating variant, we think it’s omicron and yes we, as well as many other hospitals, I’m sure in the region, are in what the CDC is calling a contingency category of staffing. We’re not yet in a crisis but we are worried.

Miller:  You mentioned that this means that they can’t be at work for at least five days. That’s the newish number put out by the CDC. Is that the guideline that you’re following right now? I ask because there has been a lot of pushback by people in the public health world and medical world saying that the CDC was too lenient in lowering the number of days that people have to quarantine?

Nolt: I don’t envy the CDC [for] having to walk this line. The signs are showing that the Omicron variant appears to be transmittable and infectious two days prior and 2 to 3 days after someone is symptomatic. So if you go five days out, you probably aren’t going to be contagious. But you’re right. I suppose you could still be shedding even five days after you start your symptoms. But two things: we have to preserve our capacity to take care of anyone; and everyone who comes into our hospital and our healthcare workers are masking and they’re wearing eye protection. They’re being very, very careful. And so I think that we have to have a balance between transmission and taking care of the patients that we’re responsible for.

Miller: It’s interesting to note, as we heard from Dawn Nolt, we actually don’t know right now.  We can’t do testing on every single person who tests positive to know [which] variant they have. Do you have a sense right now in Oregon hospitals? Who is there because of the more virulent delta variant and who is there currently because of omicron?

Graven:  I don’t have the data for that. I will say that cases are starting to show the sign of being more in the vaccinated population and that’s indicative of the omicron variant. And my guess is it is already at 75, 80, 90% of the transmissions in Oregon and that the hospitalizations are beginning to reflect that more and more. So there will be a transition as we basically move from a delta population to an Omicron population in the hospital. And that’s happening right now. You’re already seeing the increase in our census to near 500. And that will continue.

Miller: From a hospital’s perspective, is there a meaningful distinction between people who are hospitalized because of COVID and people who are hospitalized for any other reason; a car accident or a heart attack or whatever and who then test positive after they’ve been admitted?

Nolt:  That’s a great question. People who are hospitalized because of active COVID-19 infection, we know that we can give specific treatments to alleviate their disease. And that helps us direct their care for that specific disease. For people who are incidentally found to have COVID-19 [for] example if someone comes in with a fracture or trauma, it’s rare that the COVID diagnosis or virus impacts their hospitalization. The only concern thoughDave, is that once we know someone has COVID, there is a package of infection control measures that we employ. We then try to make that person not transmit further. So it does impact the resources at the hospital. Even if someone doesn’t have symptoms from COVID, the mere fact that they’re in the hospital, we will then try to prevent that infection from being transmitted to healthcare workers and patients.

Miller:  So I mean that makes it clear that there are still more resources that have to be brought to bear that could really tax any hospital in Oregon if somebody has COVID, even if they’re not using a ventilator or using up an ICU bed. But are you projecting that ICU beds or ventilators are themselves going to be in short supply?

Graven:  So far we’re not seeing them being in short supply. So, obviously, the state’s prepared for other surges in the past. However, I will say that the large majority of folks who are going to end up in the ICU are going to be unvaccinated. So that is a population we’ve seen before and for them, the virus is really not very different than it was before. So there’s still those chances.  For the vaccinated population that we are going to end up with a larger share of than we have previously, we don’t expect nearly as many to end up with those more intensive treatments.

Miller:  When you look around the country around the world, what have you been seeing in terms of pediatric hospitalizations?

Graven:  They are spiking and so we are seeing, you know, I think the easiest data for us to look at is on the east coast because omicron has definitely hit there sooner than here. And we are seeing levels that are three to four times higher than what we’re experiencing in Oregon right now. So we do think that there’ll be a surge. There will be the same situation of incidental cases where you know kids may be coming in for other things that happen to have COVID. But the load is of the ones who are going to need intensive treatment is still something that we need to prepare for right now, because this is this is this is going to be happening

Miller:  Dawn, what do you think parents of children who are too young to get vaccinated right now, meaning 0-4, need to know right now?

Nolt:  Well they need to know that children get infections from their caregivers. So to protect the young ones who cannot be vaccinated, you have to create a cocoon of protection. And so we would ask persons who interact with children - family members, relatives, school and daycare staff, to please please get yourself vaccinated. Please wear your mask as diligently and vigilantly as possible. Those are ways in which we can protect the young ones who are not able to be vaccinated.

Miller:  What masks do you think we should be wearing? Do surgical masks, the flimsy ones you can find at an entrance to a store or cloth masks, help truly when it comes to a more contagious Omicron, which seems to like to hang out in noses?

Nolt:  That’s a longstanding question. What type of mask would provide the best protection. I think the one thing I’d like to emphasize is that the mask has to be worn well and fit well. So it has to fit over the nose and mouth and have no gaps around where the mask is and where it contacts the face.  The material should be, as CDC says, two fabrics that are tightly woven. And if you want to wear procedure masks, surgical masks, medical masks, you can. But the first thing I’d like to emphasize to your listeners is that the mask has to fit well without any gaps.

Miller:  Obviously as we’ve heard before, maybe I think when we were talking about delta, this is not the way the public health authorities would want people to develop antibodies. But we are going to have many more people with some combination of natural immunity and vaccine-provided immunity after this wave passes through our populations. What might that mean going forward in terms of the future of this pandemic?

Graven: Well it is certainly the case that we’re going to build up more immunity. The issue, of course, is that we’re also subtracting some immunity right? Our ability to prevent infection has gone down substantially with omicron. So that’s the bad news. But we are still maintaining what we think is a good immunity against hospitalization. And you have to remember that comes from the ability of your immune system to remember - not necessarily get rid of it immediately but to remember what it looks like and get it put away before it gets going too badly. And so that’s expected to stay hopefully for years. But you know the odds are that there will still be a lot of Omicron infections but hopefully fewer and fewer that will be hospitalized over time.

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