Make Every Bite Count; Modify COVID Vax Dose: It's TTHealthWatch! thumbnail

Make Every Bite Count; Modify COVID Vax Dose: It’s TTHealthWatch!

TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week. A transcript of the podcast is below the summary.

0:45 Dietary guidelines

1:45 A lifespan approach

2:45 Make every bite count

3:44 Make easily remembered recommendations

4:00 Using convalescent plasma in early COVID

5:00 What are the barriers to using this?

6:01 This study sheds light

7:00 Avoiding graft versus host disease

8:01 Gave sitagliptin

9:01 An example of a beneficial side effect

9:16 Can we modify the COVID vaccine dosing?

10:15 Still end up with better pandemic control

11:15 Getting more vaccine isn’t the problem now

12:15 Protecting more people

13:14 End

Transcript

Elizabeth Tracey: Does early high-titer plasma help prevent progression to severe COVID-19?

Rick Lange: Repurposing a diabetes medicine to make bone marrow transplant more safe.

Elizabeth: Should we parse vaccines differently for COVID-19?

Rick: And new dietary guidelines.

Elizabeth: That’s what we’re talking about this week on TT HealthWatch, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a Baltimore-based medical journalist.

Rick: I’m Rick Lange, the president of Texas Tech University Health Sciences Center in El Paso, where I’m also dean of the Paul L. Foster School of Medicine.

Elizabeth: Happy New Year, Rick. This is our first real recording in the new year.

Rick: Happy New Year to you too, Elizabeth. Where do you want to start?

Elizabeth: I think we should start with the dietary guidelines because that’s our oldest one, and this voluminous document you waded through, so I’m going to give kudos to you for doing that. What was noteworthy?

Rick: It’s very comprehensive, so 164 pages. It included the 9th edition of the dietary guidelines. It actually kind of changes the focus a bit. There used to be a focus on individual requirements and individual foods. What this guideline tries to do is to address dietary patterns. They talk about the fact that these lifestyle decisions very early on affect our chronic health, not only in infancy and in adulthood, but even as we become older.

They acknowledge the fact that diet-related chronic diseases such as cardiovascular disease, type 2 diabetes, obesity, and some types of cancer are very prevalent in the US population and more than half of adults have one or more diet-related conditions. They focus on dietary patterns rather than specific foods. The third thing they do is they talk about the lifespan approach. They make recommendations for kids under the age of 2, for toddlers, for adolescents, for adults, for pregnant and lactating women, and for older adults. It’s really an overhaul of how we approach diet now.

Elizabeth: We should mention, of course, that these are published by the USDA. Some of the criticisms that I’ve heard relative to this set of guidelines is that they really did not talk very much about alcohol and some of these other foods that we know are problematic they also didn’t look at very specifically.

Rick: Well, there were some committee members that hoped that they would limit alcohol intake more and reduce dietary sugar as well. The approach they are taking is instead of hitting on an individual nutrient or food group is let’s look at an entire lifestyle and an entire lifespan as well.

Again, it’s not a one approach for all individuals. We have different customs. We have different preferences. We have different availability, so the motto is “Make every bite count.” That is let’s think about what we put in our mouth and think about how it affects our chronic diseases and how it will affect us over a lifespan.

Rather than saying, “Well, you should go from 10% to 6% of your sugar content.” You and I, we don’t measure our sugar content like that. But if you avoid foods that have sugar at all stages of your life, you will accomplish those things. Rather than drill down on these individual things that, really, none of us monitor, they try to make it applicable and something that we can use in everyday life in every stage of our life.

Elizabeth: I just have to take exception here to things, that when you say none of us monitor, I absolutely monitor my alcohol intake very carefully and the same thing is true for sugar. Here is my last question relative to the guidelines. What is the role for the medical system in interacting with these, especially as they change over their lifespan?

Rick: Really important question. We need to address this very early on. Secondly, whatever our specialties are is become familiar with the guidelines and how we can make very applicable, easily identifiable, and easily-remembered recommendations, and let’s incorporate it into our overall health because, again, 50% of the chronic diseases are diet related and we can address those.

Elizabeth: Okay. Let’s turn to an early release from the New England Journal of Medicine. This one is using high-titer plasma therapy for folks who present with early COVID-19 disease to see whether or not it prevents progression to more severe disease.

It was conducted in Buenos Aires, Argentina. They enrolled 160 patients who underwent randomization. When they came into the hospital with early COVID-19 disease, they decided whether they would use this convalescent plasma or not, which they had already tested for high IgG titers.

Basically, what they found was that progression to severe respiratory disease developed in 16% of those who received the convalescent plasma and 31% of those who received the placebo, so that’s a relative risk reduction of 48%, so pretty powerful.

The reason that I wanted to talk about this study is because what we know is that a lot of these products are sitting on the shelves in American hospitals and they’re not being used clinically here. I guess I’d like you to reflect on a) how persuaded are you by this study and b) what do you think are the reasons people aren’t using this.

Rick: The use of convalescent plasma has been somewhat controversial. There were some initial studies that suggested it was beneficial. Later studies suggested it wasn’t so beneficial. The reasons why there were some controversy was thought to be #1, did we give enough antibody to individuals for it to be effective? And secondly is, do we give it early enough in the disease process to prevent severe disease?

Well, this study addressed both of those issues. They assessed the antibodies in a number of individuals, several hundred individuals that had actually had infection, and they only found that a fourth of those had high enough antibody titers that they would use it in this particular study. They addressed individuals that were early in the disease process, so that was in the first 72 hours of having COVID infection.

They, again, had a 50% reduction in development of severe disease. I think this adds on to the other studies we had that were really not so beneficial. I really do think there’s been a lot of initially early hype, but I think that this study may shed some light into how we can make it most effective.

Elizabeth: I understand that with regard to convalescent plasma it can be very difficult to standardize. I would ask you then to contrast that against Regeneron and other monoclonal antibodies which are also sitting on the shelf in lots of hospitals.

Rick: Monoclonal antibodies are given to outpatients. This is for inpatients and those that have mild disease, and those antibodies are meant to prevent people from coming into the hospital. At least in El Paso, we have a very robust way of administering it, but we reserve it for high-risk patients because those are the patients that are most likely to receive benefit first of all.

Those are the ones that are most likely to end up being hospitalized. In areas in which there are limited hospital resources, they’re most beneficial. I can tell you that in El Paso we screen patients very actively. Those that are early in the disease process, outpatients that have high-risk features, they get monoclonal antibodies.

Elizabeth: Good news. I like that. Since we’re in the New England Journal of Medicine, let’s stay there, another good news study taking a look at a potential intervention for a very severe complication, graft-versus-host disease in transplantation.

Rick: For individuals that may not be familiar with it, bone marrow transplant is used to treat hematologic malignancies, like leukemias, for example, and other malignancies. But when the individuals receive the bone marrow transplant from a donor, sometimes those donor cells actually have T cells that can attack the host. We call that graft-versus-host disease. It manifests in a lot of ways — some skin reactions, some GI reactions — and it increases the risk of death as well.

Early on, some investigators were using a known diabetic medication called sitagliptin and then they noticed that when they were using it in the animal models, that it just seemed to prevent graft-versus-host disease, which is not what they were looking for, and then they thought, “Well, I wonder if it will do the same thing in humans?”

This is a phase 2 trial of 36 individuals, who were all getting bone marrow transplants, and in addition to the usual immunosuppressive agents they got, they also gave them sitagliptin. What they noticed is only 5% of individuals ended up with graft-versus-host disease. Historically, that number would be 25% to 50%.

You always wonder, “Well, gosh, will it have some adverse effect? Will it increase the risk they’ll have recurrent cancer or somehow affect chronic graph-versus-host down the road?” The answer is it didn’t do either of those.

Keep in mind this was a small study. There were no control patients and there was only 36 patients, so we need to expand this to a larger trial. But it’s really encouraging because it’s a medication that we have access to, it’s well tolerated, it’s an oral medication, it’s inexpensive, it’s simple to use, and it’s just being repurposed for this.

Elizabeth: It is a really exciting result. It’s one of those things that of course everyone is looking underneath all the slimy rocks and everywhere they can for repurposing medications for COVID-19 for sure right now. If one of the benefits of doing that is being able to repurpose for other applications, I think that’s really great. That’s not what happened here but there’s a lot of it going on.

Rick: Yeah. This is an example of how a medicine, they were looking for a particular effect and they noticed that one of the side effects was beneficial. This is a good news story. This could change the face for individuals that get bone marrow transplants.

Elizabeth: And maybe other kinds of transplantation also.

Rick: Yep.

Elizabeth: Let’s turn finally to Annals of Internal Medicine, their COVID-19 site, something that’s in the news in spades right now all over the world, can we modify the vaccine dosing schedule so that somehow we could enable more people to get vaccinated and potentially get to that magical herd immunity which none of us really knows what that number is with regard to COVID-19?

In this particular issue, there are three different institutions that are taking a look at modeling for how we might modify this dosing schedule, one of them from Yale, the other one from the University of Washington and the Fred Hutchinson Cancer Research Center, and the final one from Stanford, all suggesting different models that could be used that would either modify or even eliminate the second dose of the vaccine for many of the vaccine strategies that are out there right now.

Almost all of them are saying that we’re still going to end up with better pandemic control if we just give a single shot. The editorialist objects a little bit to this and doesn’t really help, I don’t think, in helping us examine the ethical aspects of this. I understand the scientific standpoint that we have no data that looks at what happens with a single vaccine and I’m struggling a little bit, having received the single vaccine, with spreading the wealth so that other people can get at least partial protection.

Rick: These are all great hypothesis-generating articles and studies and comments, but they’re really unproven at this particular point, and so we’re weighing what the scientific evidence provides, and that is these two vaccines in the US that have 94% or 95% efficacy after the second dose. If you looked across what’s happening in the US right now, it’s not that we’re limited by the number of vaccines. The major story in the news is we can’t administer it fast enough, so getting more vaccine at a time where we really haven’t rolled out plans to adequately distribute it doesn’t seem like it’s a strategy for success either.

This issue about you don’t need the second dose, we really don’t know that. The first dose confers immunity. The second dose confers additional immunity — it’s a booster — but it also confers durability as well. It looks like that after the second dose you have more antibodies, protective antibodies, than you do if you’ve had the native infection. We know that you can get a reinfection after a native infection.

I’m loath at this particular point to tell people, “Oh, you don’t need the second dose.” I think that’s the wrong message at this particular time. We just don’t have enough data. Let’s make sure that the vaccine we’re giving is effective. It’s effective for a long period of time and we can distribute it as quickly as possible.

Elizabeth: Clearly, even Operation Warp Speed has said, “No, we’re going to stick with this 2-dose regimen for the time being.” I think my struggle is really when I look at these models — and admittedly they’re models that come up with numbers relative to herd immunity protecting more people — it seems like it could happen with the distribution of a single vaccine to more people.

Rick: Your point is well taken, that these are models and they make assumptions. You assume after the first dose you know what the long-term effect will be — that’s why we can make these models — and the answer is we just don’t know that, so we don’t know if the models are correct.

We also know that immunizing the people that are most vulnerable ends up being the most important and the vast majority of other people do very well despite infection. It’s very rare that those people have severe infections. If we target our vaccinations for those particular groups, we’ll achieve significant safety here in the United States, even with COVID infection.

Elizabeth: On that note, that’s a look at this week’s medical headlines from Texas Tech. I’m Elizabeth Tracey.

Rick: I’m Rick Lange. Y’all listen up and make healthy choices.

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