Think Out Loud

What to know about the new COVID-19 variant and fall boosters

By Rolando Hernandez (OPB)
Aug. 14, 2023 5:21 p.m. Updated: Aug. 14, 2023 7:50 p.m.

Broadcast: Monday, Aug. 14

File photo from Feb. 8, 2023. More than 17% of new COVID-19 cases in the U.S. come from the EG.5 variant, also known as Eris. It currently is the dominant variant in the country and the World Health Organization has classified it as a "variant of interest."

File photo from Feb. 8, 2023. More than 17% of new COVID-19 cases in the U.S. come from the EG.5 variant, also known as Eris. It currently is the dominant variant in the country and the World Health Organization has classified it as a "variant of interest."

Kristyna Wentz-Graff / OPB


Across the U.S., COVID-19 cases are on the rise. The new variant EG.5, also known as Eris, has been circulating the country for the past six months and currently makes up more than 17% of new cases, according to the CDC. At the same time, a new vaccine and booster is expected to be available by the end of September. Corey Casper is the president and chief executive officer of the Access to Advanced Health Institute in Seattle. He joins us to share more on the new variant and the booster expected to be released this fall.

This transcript was created by a computer and edited by a volunteer.

Dave Miller: From the Gert Boyle Studio at OPB, this is Think Out Loud. I’m Dave Miller. COVID-19 cases are on the rise, once again. According to the CDC, the variant EG.5, also known as Eris, now makes up more than 17% of new cases. Meanwhile, a new vaccine and booster are expected to be available this fall. Corey Casper joins us to talk about Eris, boosters and more. He is the president and chief executive officer of the Access to Advanced Health Institute in Seattle. Welcome back to Think Out Loud.

Corey Casper: Thanks so much for having me, Dave. Nice to speak with you.

Miller: Likewise. What do we know about the Eris variant at this point?

Casper: So the Eris variant is the latest of variants of interest that have evolved over the course of the pandemic. What we know is that it doesn’t appear to be necessarily more pathogenic or in other words, it doesn’t appear to make you more sick than the previous variants that we’ve been experiencing over the last several months. And we’re not quite sure how transmissible it is, but it seems to be very similar, clinically, to the previous variants that we’ve seen. What makes it a little bit unique is that it has a mutation that makes it not particularly well rendered by the previous vaccines that most of us have received.

Miller: What about previous immunity from natural infection?

Casper: Yeah. Unfortunately, for people who have been infected with the previous Omicron variants, this is anything prior to XBB.1, which is what had been circulating until recently, there’s not a lot of natural immunity. And unfortunately, the vaccines and the boosters are not providing a great degree of immunity either.

Miller: So given this new variant’s ability to escape our existing versions of immunity, it seems lucky that, as you said at the beginning, that it’s not more pathogenic.

Casper: Yeah, we are fortunate. And I think that with each of these new variants of interest or concern, we hold our breath and, and really hope that they’re not going to be more dangerous than ones that we’ve seen in the past. But I agree with you, it’s really relying on luck.

Miller: Even though cases are rising right now, I’ve seen two big arguments for why people should wait another month or two before they get a booster. The first is that the next round of boosters, they’re likely to be more effective against this strain or other dominant strains than the current boosters are. Do you agree with that argument?

Casper: I do, with one small asterisk. So I think that we are at the point of our pandemic now, where we recognize that the most significantly affected are our most vulnerable. So, if, for some reason, you are someone who is especially susceptible to doing poorly with this virus - if you’re elderly, if you have a condition that compromises your immune system - it may not be safe to wait as cases rise if you’re not able to isolate yourself. With that one exception, I would agree with you.

Miller: OK. And then, the second argument I’ve seen for waiting is that it could increase the chance that you would have the maximum protection through the winter, which has seen waves of COVID in November, December or January for three years now. What do you think of that reasoning?

Casper: So we absolutely know that the duration of immunity that you get from the current RNA vaccines is probably on the order of four months. So, if indeed, like most respiratory viruses, we see a surge in cases in the winter, and you get vaccinated now, that would leave you unprotected as early as January. So I think that, for that reason, with the RNA vaccines, indeed, waiting could be a good idea, both because they’ll be reformulated to contain a variant that will be much more protective against at least what’s currently circulating, and because they’ll last longer.

The only possible exception to that is that there is now a new choice that we haven’t had before. That’s a new type of vaccine. It’s actually an old type of vaccine, a protein-based vaccine with a strong immuno-stimulant called an adjuvant. That vaccine is made by Novavax. It works differently from the RNA vaccines and it’s possible that the duration of immunity from that vaccine may be a little bit longer, but we still don’t know that.

Miller: Meaning it hasn’t been around long enough for us to know how long the protection lasts?

Casper: Correct. But what we know from other protein vaccines that include strong adjuvants is that a hallmark of those vaccines is that they tend to last a little bit longer. So time will tell if that’s the case with this vaccine. But we can maybe hold out some hope for that.

Miller: I want to go back to the language you used because it’s important here and I’m not sure that I’d heard that before. You said that if someone takes the RNA vaccine now, that come January, they might be unprotected again; are you saying that not only do these vaccines… that the protection we get… that they wane over time… but four months after you take it, it’s as if you hadn’t gotten a booster four months before?

Casper: Well, again, let’s be really specific. So what I would say is that it’s clear that you retain some degree of immunity. Someone who’s received an RNA vaccine even many months ago, is not the same as someone who’s never seen the virus and never gotten a vaccine. But in terms of robust protection from what we know protects you, which are neutralizing antibodies, those really do drop to levels that are not sufficient to protect you within four months of receiving that vaccine. It does leave you with potentially other arms of your immune system, your cellular immunity that could still protect you. But yes, the strongest part of your protection wanes four months, maybe at most six months, after receiving these vaccines.

Miller: And are we talking about the difference between not getting sick at all, not contracting the virus when you’re exposed to it, or the high likelihood that if you do get exposed and do get sick, it’s not going to be a serious case. It’s not going to, say, require hospitalization. Those are two very different goals of the vaccine.

Casper: Yes, absolutely. And thank you for highlighting that because it is nuanced. So first, I would say that none of the vaccines that we currently have right now do a great job of protecting you from being infected. That’s something called ‘sterilizing immunity’ and almost none of these vaccines do that, well. What they do do, as you mentioned, is prevent you from getting clinical signs of the infection. Why is that important? Because as we know people who are vaccinated, with the current vaccines, still can transmit this virus to others that they come in contact with. So even if they’re not sick, they’re still able to spread the virus.

So you’re right, when we talk about the efficacy of the vaccines, we first need to talk about whether they can prevent one from being infected. That’s probably the minority of people who get vaccinated with these vaccines. The next step is, do you get sick at all? And these vaccines, when they are given within the last four months, are very good at preventing, I would say, mild to moderate illness. But what happens is, [when] you get beyond four months, they become not so good at preventing mild to moderate illness and people can get sick. Now, they do remain some activity in preventing death and preventing hospitalizations. So that’s the continuum.


We are fortunate that both with previous infection and even with remote vaccination, we remain protected from what are the most serious consequences, hospitalization and death. But that is only until the virus mutates to something that is unrecognizable by the immune system. And unfortunately, what we are seeing is that the virus continues to mutate and that still remains a possibility.

Miller: My understanding is that other vaccines for other diseases have been historically more effective at achieving what you called sterilizing immunity, so you simply will not get sick from those viruses, say. What’s different about either COVID-19, this novel Coronavirus that causes COVID-19, or the vaccines that for the most part don’t achieve that level, they don’t give us that level of immunological response?

Casper: Yeah, great question. I would say there’s a number of things that contribute to that. So first and foremost, I think this virus is different from other viruses in that all viruses need something called a receptor that sits on your cells to get into your cells and cause problems. If the virus can’t get into your cells, an RNA virus, it can’t cause problems. So the types of receptors that this virus uses are widely found throughout multiple different types of cells in your body – which means that very quickly, this virus can get access to many different cells in your body. With something like influenza, that virus accesses a receptor that is really most commonly found on your respiratory cells. And so by blocking that interaction, you can really block widespread infection of cells. This COVID virus can quickly infect multiple different types of cells through this widely used receptor, and that makes it difficult to prevent entry.

So essentially, you’re guarding multiple doors instead of just guarding a single door. And that makes it very challenging.

Miller: And that also perhaps helps to explain why COVID-19 can affect so many different systems in the body because it can infect so many different cells in those systems?

Casper: That’s exactly right. And it probably is also why we’re seeing these manifestations of long COVID, because the virus gets into many different types of cells and it’s difficult for the body to completely eradicate it from those cells.

Miller: The federal government, the new vaccine that they have recommended and authorized that hopefully will be available as early as late September, maybe later... my understanding is that it’s not going to be so-called ‘bivalent.’ Can you remind us what that means and why federal authorities are going back to a sort of simpler version of a vaccine?

Casper: So the federal authorities made a key decision that many people may have been following, but some may not have. The decision that they made is that the approach we will take to COVID is similar to the approach that we take to flu, which is essentially that [for] viruses that mutate frequently, we’ll try and make a prediction as to which strain will be circulating and we will encourage vaccine manufacturers to make a specific vaccine against that strain. So a few months ago, when Omicron was still evolving quickly, first of all, there were multiple strains circulating and secondly, the RNA technology had matured to the point where it was possible now to give more than one strain together. This is something we do every year for the flu vaccine, which typically contains either three or four circulating strains. And so for COVID, we adopted the same strategy and tried to include two strains, what we called ‘bivalent,’ and put those into the same vaccine. What we found at the time was that that was modestly successful. Really, some data suggest it wasn’t much better than just having the original single strain vaccine. But at least it showed that with this new technology, that was possible.

Moving forward, what the epidemiologists and biologists have told us is that the dominating strain, at least at the time when this decision was made in June, was something called XBB.1, and because that strain dominated and there really wasn’t another strain that seemed to be emerging as an important one, vaccine developers were encouraged to make a vaccine against that single strain. So we are now back to a mono-valent vaccine. Unfortunately, what we’re seeing now is that decision was made three to four months ago, and now the situation has changed where there are multiple strains circulating, but we just can’t make a new vaccine up with the current technology that quickly. So we’re behind the eight ball.

Miller: You noted that federal authorities are now basically going to be taking a page out of the influenza, the flu vaccine playbook. But we don’t get boosters for the flu vaccine every three or four months and it’s not at all reasonable to expect that large numbers of Americans are going to do that. Obviously, it’s been hard to convince some not insignificant percentage of Americans to get a single shot, let alone follow ups. So, where does that leave us?

Casper: Yeah. So I would agree with you that I’m a bit critical of that decision that was made. So this is a different virus than influenza in the sense that it is not necessarily seasonal. So we’re seeing an outbreak now in the hottest days of the Pacific Northwest…

Miller: And I mean, we’ve seen waves in previous summers where there have been waves in the summer and in the winter. This is a kind of pattern. I think it’s happened enough that we can call it a pattern.

Casper: I would agree with you, and I would say to you that that will continue. And I think public health authorities recognize what you mentioned, which is that the public has fatigued of getting boosters. And so the hope was that an annual shot would at least provide sufficient protection to protect people from death or from severe hospitalizations. I think that in the ideal scenario, public health practitioners would follow the science and would have people vaccinated every three to four months, but it’s not feasible. As you point out, less than 20% of people have even gotten the most recent booster.

So what that says to me is that our policy is a little bit misguided in two ways. One, the hubris that we have in thinking that we can accurately predict that variant that will be around four months later, I think has proven to be foolish. And on top of that, we haven’t emphasized technologies that could lead to more durable vaccines. There have been vaccines that have been recently approved that we know last more than 10 or 11 years, even in people who are in their eighties and nineties. So there are technologies which would give us more durable vaccines, but we’ve chosen not to invest in them.

Miller: But would those vaccines that you’re saying have recently been approved and proven to give us say a dozen years of protection, is there reason to believe that they would work for this novel Coronavirus?

Casper: Yes. So there was evidence in the first, I would say, year and a half of the pandemic that suggested that we could develop vaccines, that people are now calling next generation vaccines. These are vaccines that provide a broader degree of protection, so not only against the strain that’s in the vaccine but against future circulating strains, and that you could make these vaccines more durable. Unfortunately, the government has decided not to prioritize the development of those vaccines, nor have pharmaceutical companies which right now, are you quite happy with the vaccines that they have at present. So, unfortunately, that was a strategic decision that we made that’s now impacting our ability to control this epidemic.

Miller: How do you explain the latter point you just made? I mean, it seems to me that there would be a lot of money to be made by a pharmaceutical company that created a COVID vaccine that had a good chance of being the last one anyone would need for more than a decade. I imagine that that would be an investment that could pay off. Why aren’t they pursuing it?

Casper: Well, I think the economics of that one are tough. So what I would say to you is if you look at the trend in pharmaceuticals, there’s been a trend now for companies to prioritize things which you need to take chronically for the rest of your life. So if you look at things that pharmaceutical companies are emphasizing right now, there are medications for things like endocrine disorders or blood pressure or cholesterol or weight, which need to be taken for the rest of your life. And that sort of builds in a market. You know, if you developed a vaccine that you needed to take only every 10 years, compared to one that you needed to take every three months, it’s a significant fewer number of doses you’re selling.

So I’m sorry to be so cynical, but I think that last year, Pfizer and Moderna made $32 billion on selling their COVID vaccines. You know, I think that there were people who thought if they can continue to get people to take these vaccines as the government was recommending, that would be much more lucrative than coming up with something that would be ‘one and done.’

Miller: OK. That makes sense. And I clearly do not think like a pharmaceutical executive because I’m not one. But then what about the former point? Why do you think the federal government hasn’t put more federal research money towards these efforts?

Casper: Last year, the National Institutes of Health, which is really one of the main drivers of innovation in the early stages of vaccines, I think spent about $36 million and this is tens of million, a billion-dollar budget. So a fraction on new COVID vaccines. And I think that there are several reasons for that. One, I think that many people felt as if the current vaccines and the vaccine manufacturers and the strategy of predicting that next variant and chasing our tails to make it… I think they thought that would work. I think some thought the pandemic may actually end and fade away. And finally, I think that there is a political fatigue as well. I think that this is a difficult issue, and it doesn’t have support anywhere on the Hill. So I think, if you’re a Republican, the COVID pandemic is not something that continues to play well with your constituents. And I think if you’re a Democrat, and similarly, I think that it’s a weakness that’s perceived on many Democratic, politicians to remain focused on the severity of the COVID pandemic.

So I think it’s an issue that most people want to sort of sweep under the rug and see go away. And I think we’ve taken more of an ‘ostrich with our head in the sand’ approach to this than one that is really rooted in vaccine technology and public health science.

Miller: Corey Casper, thanks very much for joining us.

Casper: Thank you so much for having me.

Miller: Corey Casper is the president and chief executive officer of the Access to Advanced Health Institute in Seattle.

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