Our weekly question and answer session with Fred Goldstein, Dr. Luis Saldana, and Nick van Terheyden, MD on our COVID Insights to Action Discussion webinar that takes place live every Wednesday at 4pm ET You can register here https://bit.ly/C19QandA
Fred Goldstein
Hello, everyone, and welcome to this week’s COVID insights to action discussion group. I’m Fred Goldstein. I’m joined once again this week by our two esteemed physicians, Dr. Louis Saldana and Dr. Nick van Terheyden. So thanks so much for joining us this week, we’re gonna be discussing herd immunity. Is it a mirage or not? There’s obviously a lot going on, people think about the vaccine, etc. So why don’t we begin with perhaps defining what is herd immunity? Who would like to take that one on?
Nick van Terheyden
We both pause for thought and think is there an actual definition that we can use and refer to? I think that’s part of the challenge is that it’s not a fully defined concept, or certainly not one that is accurately or clearly defined to say, x percentage of people, I think that’s what most would look for, and say, Gosh, if we got to 60% of people who have had disease x, and based on what we know, that would determine that nobody is likely to see or get the disease, the disease will diminish the honours, or the spreadability of the disease will diminish. That’s the problem. We just don’t know. If I was to sort of hazard a generalized definition of this, it would be herd immunity is the point at which a disease that is spread through populations ceases to spread naturally. And that process of spread no longer occurs and what what remains is essentially small remnants or potentially minor outbreaks.
Fred Goldstein
Yeah, so essentially, it’s that you have enough people who are immune to it, that if you happen to come into contact with somebody, either your immune or their immune and so you’re less likely to pass it on. And I do understand from what I’ve read that that it depends upon how infectious or contagious the individual disease itself is. So if it’s highly contagious, it may require more people to reach a herd immunity, whereas if it’s less likely to be spread, it takes a lower number so I’ve seen some examples where they talk about 94% being an estimated number for herd immunity associated with measles obviously with COVID is different with the flu it’ll be different
Nick van Terheyden
so before you before you move off that I think it’s important to understand the the spread ability of measles I don’t know that it’s the most but certainly based on my understanding and you know, experience or exposure to virus science not to the actual viruses although I can’t recall whether I have measles or not that has an R value of 18 so for everybody measles case 18 people get it so that’s why the herd immunity level is so high.
Fred Goldstein
Well, I hadn’t heard that number before That’s amazing.
Luis Saldana
Yeah. Yeah, that’s I think that kind of leads into a little bit more kind of discussion on the definition or the your your right Nick the other that brings up his reason are not with so high for for measles was the it because it is a pure aerosol. So I think this also lends what we’ve talked about aerosol of the COVID of the SARS COV-2 virus, it’s not a pure, it’s not pure. I think there’s a combination here that we’re dealing with otherwise we would see what we saw with measles. It’s not a pure aerosol type thing. But But what what I will say is Yeah, I think with herd immunity, we’re talking about knocking down that R0 just what Nick said, they basically to, you know, you’re suppressing it as far as you can, I think that that’s kind of the the goal one way or another. You know, I’m not sure that I can say this, they remember that with the 1918 flu pandemic, you know, there was certainly no vaccine, how it kind of played out in terms of herd immunity by natural infection or not, I think that’s what people kind of think, but I think there was some mutation actually may have led to, to, to some drift, some genetic drift, at least, that lead to kind of a better outcome. And that could happen here with variants, I’ve always saw it seen the flip side of the variance, and it could play out it could drift into not being as as infectious in the long term, but we just don’t know, but, but I think the important thing is, is we because of the still the high the relatively high death rate with with the SARS, COV-2 infection, and the kind of unusual nature of it, and the burden on the health system, that vaccination is going to be the only way to get there. For you know, for the world, we saw the failure of Sweden, you know, on trying to do with natural infection. And, and, and, and, you know, that that was a massive failure, you know, and sort of can see that, and when, you know, certainly we had the proponents of that approach here, in the previous administration, that, you know, the we’re actually I think, you know, leading us down that path. So, so anyway, a lot of lessons there, I think
Nick van Terheyden
I And maybe a quick refresher on aerosols and droplets, because that’s come up, cause I the odd piece of confusion, droplets. And to be clear, please, nobody hold me to the purity of tsciencehis sign. So I tried to simplify as much as possible, because I think people spend their whole careers studying this area, but droplets tend to be larger, and are affected more by gravity. So they tend to fall as a result of being expelled, and then gravity drops. And so they don’t hang around as long. aerosols tend to be lighter, and float a bit like those feathers that you see floating by or leaves a plant by in the wind. And that’s, you know, a difference in the spread ability, because now you have to think differently. And I think, you know, importantly, relative to measles, it’s fully aerosolized. So it just hangs around, it just doesn’t dissipate at all, which, you know, not the same for COVID-19. But there’s a mix of that, and we don’t know exactly.
Fred Goldstein
So, you know, getting back also to Luis, what you’re talking about, there are really two ways to achieve herd immunity. You either get enough people infected, or you get back enough people vaccinated or some combination of that, right.
Luis Saldana
Yeah. And again, I think it’s like infinity. If we approach it, we don’t return me. That’s the way I see. We approach herd immunity that we saw with measles, measles was still out there. You see, whenever vaccine rates drop, or certain populations, measles comes back, and I think that’s that’s probably what we’re looking at with, with this virus as well. But you know, but you know, I think so I think we only have by view as you approach Herd Immunity , you know, you never, you never reach it, you know, we do see these outbreaks small around the world of various things that we’ve essentially vaccinated for, and kept people from getting. The other thing I thought was interesting, as I looked into this, was this concept that yes, there for those diseases that don’t have a vaccine, you may have a large substantial group of your population who are adults who are immune because they’ve been exposed, but the children and those who haven’t, then create an environment where that disease can then come back in and begin to spread again. So you always have that ongoing issue with it, you never achieve the full herd immunity. What are some other things that people should consider around this issue? For example, Nick, I know you were looking into the issue of what do you do with somebody who’s already had the disease and this issue of vaccinate or not vaccinate?
Nick van Terheyden
Yeah. So I think that’s a great point, you know, question that comes up occasionally for those that have been unfortunate to suffer the disease. So they develop COVID-19 because they were exposed for some reason. You know, potentially, some of these people even had very mild causes of the disease or only discovered that they had the disease because they went and got a test, maybe there were contact, discovered that the contact was positive, they tested they were positive. So all of those variations and you know, all the way through to intensive care where you had, you know, severe disease. At the end of that our body produces antibodies to the COVID-19 virus. And if you were to be exposed to that same virus, the body typically responds and says I recognize that are so I’m going to combat it. And you develop some level of immunity. So some things to clarify here. First of all, we don’t know how long that immunity last, we’re not certain we see probably three months, it could be longer. Two we don’t know if that immunity is consistent or the same if you introduce a vaccine, which is essentially a proxy, it looks like a virus induces the same antibody response, but it’s different. And you know, what we understand about the antibody responses. It’s very complex, and there are lots of contributing factors that allow you to essentially neutralize that virus. So here’s the data that I think is interesting and relevant for people that have had COVID-19 and are asking themselves, should I get a COVID-19 vaccination. And to be clear, this is a pre published study. So it has not been peer reviewed. And it’s a small number, it was actually 10 patients, and they received either one or other of the messenger RNA vaccination from Pfizer or Moderna. But significantly, that those individuals all showed a steady decline in antibodies, that doesn’t mean say they’re not resistant to the disease. But certainly we see that they still have B cells that will, you know, have memory and might reproduce it. But they saw a thousandfold increase in the antibody response titers of neutralizing antibodies. That to me is worthy. And you know, to Luis’ point of making sure that we reach herd immunity and ensuring that that immunity persists. I think the answer to that question, if I had had COVID-19, I will be saying to myself, I would get the vaccine to boost my immunity. But I would be low down on the priority list trying to offer others the opportunity to, you know, to get the vaccination ahead of time, or ahead of me.
Luis Saldana
Yeah, and I actually I know a lot of frontline clinicians that got it and got the vaccine in the first very first way, both doses, I think that we should talk about the printed preprint suggests the one dose is probably the right thing, which makes sense, because the first dose we receive of the vaccine, at least the messenger RNA vaccine, just kind of priming the pump. And that’s what the original infection probably does. The second infection is where the where the money is, that’s where the money really lies in terms of really revving up the the immunity, that’s going to be more, you know, more predictable and more probably more durable as well. And and because you know, the variable on infection, unnatural infection is you we know there’s people who are totally asymptomatic and we know there’s people who have severe illness, but we don’t know totally how much of that is viral load. That’s it could be a significant portion. So if you have a asymptomatic, very mild infection, your body didn’t probably may not have produced that kind of response. We don’t know. You just saw a little bit of the virus. Your body responded a little bit. We don’t know enough on on that. But clearly, I think the recommendation I would say is at least get you know if you’ve had COVID get at least one you’re one of the messenger RNA probably the you know we had a one dose or possibly even I never studied the J&J but or get the J&J and as well, but but that’s what I think that would be a recommendation.
Nick van Terheyden
And then a small translation for that’s where the money is phrase that Luis uses. But what that typically means in practice is that when you feel the impact of vaccination and you feel a bit, you know, under the weather, that’s your body going, whoa, let’s pack it in and attack it. It’s not always there’s some variation in that. But certainly, that’s that’s what’s happening and that sensitizing first doses, essentially, in the cases of people that have had it, you’ve already had it. So your body’s already I’ve seen this before, let me go and attack it.
Fred Goldstein
Yeah, you know, just an interesting aside on that, I was watching some of the news and they were showing the big vaccination site that the army set up out in LA that was just running like clockwork, you know, they were putting them through and, and one of the women finished up and she said, Yeah, I’m so excited. I got Sick a few months ago with COVID. And I got the vaccine, you know, and so you can see people are beginning to understand the importance of this, which is good to see a lot of people and you sort of touched on this, Luis, say, look, you know, if I get sick, it’s not gonna be much or the vaccine, you know, why should I do this as a younger person, but we’re really seeing effects and not knowing what some of the effects are right? over a longer term.
Luis Saldana
Yeah. As far as the infection, yeah, certainly, I think even more data around around Long COVID. Even in, even in young people I think is emerging, we, you know, we still haven’t fully studied the experience with this. And I think just because somebody wasn’t hospitalized, doesn’t mean they can’t have long term sequelae from this infection, and I would not take that lightly at all. I, you know, I don’t think this is not something you want anybody to get the infection, because we just don’t have all the information on it. And I’ll say, we have a scientific miracle with these vaccines, you know, I think we need to be, you know, from every rooftop screaming about this, and, and, and really gain everybody to pitch in and, and take this and get it because, you know, we will hit the point where the vaccine hesitancy will be a factor, you know, right now, there’s more, you know, more demand and supply, but that’s going to probably change at some point. But But I still feel like our best route out of this is not only us in the US getting fully immunized vaccinated, but as much of the world that will be vaccinated if we want to start traveling again, and, and doing those types of things, we want the whole globe to be to have the vaccine available to them as well.
Nick van Terheyden
So I think the other part of the answer to your question, Fred is, well, why don’t I just let everybody else get the vaccine, and you know, that will give us herd immunity. If herd immunity is 70%, you know, pick a number randomly, I’ll be in the 30%, I don’t need to worry about it in all avoid getting. And this always reminds me of the story I remember from my childhood, where everybody got together and said, wouldn’t it be really cool if we all jumped up and down at the same time, and we could make this really loud bang. So everybody gets together? You know, clock strikes midnight, and there’s stony cold silence, and of course, everybody’s stood there go, Well, I’m not going to jump because everybody else is because I want to see what this is like. And, you know, I’m telling the story a little bit humorously, but it’s important. There are people that cannot have the vaccine for a variety of good clinical reasons that preclude it from having it, you know, not going to go into those details. But for those of us that can, it is an imperative that we contribute, it’s our way of protecting and one of the things that I saw with flu vaccination programs that were effective in getting people to participate was not so much the message of protecting you, but protecting the people that you love. So for, you know, younger folks. Yeah, maybe you won’t have a severe disease and to be clear Luis’s right, you could and you might have this long tail, which is awful, and we’ve still got to understand it. But even if that’s not the case, don’t you want to contribute to your family, your elders, your parents, grandparents, and all the people around you. So I would say it’s an imperative. I say it clearly, anytime somebody shows up, I will take my vaccine the instant that I’m eligible, and I’m an appropriate you know, position in the line as it’s being defined in terms of priority.
Luis Saldana
Counter one more I’ll take your spot on that. Can I just say one more thing because I think your your approaches on getting people with vaccine hesitancy overcome that is his spot on the stories trumpt facts and figures don’t try and wow them with with numbers. If somebody has vaccine hesitancy just put it in a story like you said, Man, I really want to protect my see my grandmother. One more time I want to do Thanksgiving or you know, Christmas with with my with the families in a way that I don’t threaten their safety and things. And so you know, I think leading with stories like that is makes it a lot more powerful than facts than facts and figures.
Fred Goldstein
Let’s sort of wrap four ideas together, which I think are interesting. We have a vaccine. As you said, Luis it’s really kind of a miracle. Incredible. work to get it in a unique way to create vaccines. You also mentioned earlier this whole issue of variance, and we’re seeing more variants that may have less of an ability to be impacted by the vaccines. And we’re trying to hit herd immunity. So when you think that through, if we do get to the point where a variant is less likely to be impacted? Isn’t it true that the newer type of vaccine approach with mRNA can rapidly produce something against that if we do need boosters or other shots in the future?
Luis Saldana
The answer is yes. But But the other thing I’ll say about the variances, we only think of them going one way that’s becoming a monster. And like I said, I think with the 1918 virus, we may have seen the other the genetic drift that carries it off into oblivion. Viruses are not smart they have and we try and make them sound smart. But but they’re not. And they can they can make these genetic things that happen, can make mistakes and actually carry the way but yes, absolutely. With the current technology, we can we can make very rapid adjustments. And, and it’s been okay, that there have to do full trials to to, you know, to do those updates. But but actually just, you know, just for a booster shot or something like that, which is still a possibility. We don’t know that yet. We’ll see what the wait, right.
Fred Goldstein
And just to add to your point, I think it’s when you think about that, you know this very well, or he’s having to work with Ebola, if you have a virus that is super virulent, and kills everybody right away, there’s no chance for it to spread. So it does the mutations have to in essence, reduce the virulency if that virus wants to continue on.
Nick van Terheyden
Right. And the other thing I would say relative to this is that, you know, Luis is right could go either way. And you know, but what we want to do is to limit as much as possible of the spread for people getting the disease, the way to do that is to work all avenues. And that’s, you know, non pharmaceutical interventions that we’ve talked about, like face coverings, distance, cleanliness, and then actually the vaccines as quickly as possible. And the underlying reason for this is vaccines change, I’m sorry, viruses change, that’s what they do. You know, I love the point that Luis made, you know, they’re not smart, they’re not this is just sort of, you know, these are errors, essentially, that are happening in the replication process. Maybe they were designed in as part of that process to allow them to sort of go in various directions. But this is not intelligence. And the less opportunity they have to replicate, the less opportunity they have to go in these directions, good or bad. And the sooner we compress it down and make this disappear as much as possible, the less that becomes an issue. So faster, quicker rollout. And Suppression of virus is our primary goal in everything that we’re doing.
Fred Goldstein
Great. If anyone has any questions, please feel free to drop them in the chat box. We’d be happy to answer those for you. So looking, now we’ve got a dropping nicely declining rate of infections, deaths, etc. Have we reached herd immunity?
Nick van Terheyden
You’re a naughty boy.
Luis Saldana
Yeah, yeah. Yeah, I think you can look at the way this this has played the pandemic has played out in waves, right?
Fred Goldstein
Yeah,
Luis Saldana
there’s these waves is like these successive waves. So we’re on the downside of the wave is essentially of wave number three, actually, if you look at the case, numbers, they’re much higher still, then then then wave number two, even though they’re they’re on the way down, which is good, good sides, you know, for, you know, to be hopeful, as far as that goes, and also gives us gives us the opportunity, as Nick said, to really drive down that R0, I think this is our opportunity that and the vaccines based on what we’ve seen from the experience in Israel, we talked about that last week here. But with the I think what we’ve seen from Israel is we can we can render this virus, almost non lethal and we can make it if people talk compared to the flu, we can make it like the flu actually, the in that it’s lethality and seriousness is much, much lower than what it is. And so it won’t be a dangerous virus anymore. It’ll just be you know, it could be you know, it could really be driven way, way down. And I think that’s, that’s the real goao. There’s also I think some seasonality of this that we don’t understand why we’re seeing is these waves I don’t know what we’re doing. Certainly the last peak was driven by holiday, you know, interactions and things like that. So, indiscretions maybe will say,
Nick van Terheyden
you know, I think it’s interesting. I wonder if 18 months ago, what the percentage of people that knew what a Coronavirus was, or could even talk to it. Yet now it’s sort of preeminent because of the pandemic effect and the severity of SARS COV-2. And if I’m wrong, forgive me, I it’s either, I believe it’s four or five other Corona viruses that are circulating naturally, in the human population, they cause somewhere of the order of 15 to 20% of common colds, you know, to Luis’ point, they just don’t do the damage that SARS COVID has been doing. And we will get to that point, the question is, how quickly we can do that. And all of that is on us, you know, science, to your point, earlier, has done a phenomenal job, you know, when we talk about safety, you know, worth reiterating around the vaccines, they are not one year in development, they are 30 plus years, you know, at least 20, from the origins of that platform that you described, Fred, in your commentary about, you know, changing them. And I think we’re gonna leapfrog into other opportunities. I think it’s just it’s accelerated this knowledge and insight to the point. And we’re very fortunate because if this had happened 20 years ago, I don’t know that we’d have been in the same position, we I very much doubt we would have had to let alone three and as it is, I think 11 vaccine candidates and phase three trials. Last time I looked, that’s incredible.
Luis Saldana
Yeah, for sure. For sure. Well, I’ll say one more thing, just because I take the crediting the vaccines, I think there’s one thing from that that’s suggested by the Israel experience, is that it actually does drive down transmissibility, we can draw that conclusion. So I’m not saying this is scientific fact. But there’s some suggestion that it’s driving down the virus load and prevalence in in people and that, which takes down the low the the overall virus level in the population. And so it’s by doing that it reduces the transmissibility. So, you know, again, I think I’m trying to maybe build a case for for everybody getting their vaccine, because that’s what I want as selfishly. That’s what I like to see.
Nick van Terheyden
Right. I think the the data that I saw specifically talked to that documented a 67% reduction in positive swabs, amongst those that were vaccinated, which essentially supports that notion that this is not only protecting you from the disease, but also the true risk of transmission, which is absolutely fantastic news.
Fred Goldstein
Right? And when and just you know, as we sort of come to a close, we got a few more minutes, as you consider this from, you know, the risk of the disease, the data from the vaccines is showing unbelievable impact on how sick you get, isn’t it? You take that vaccine, and I don’t know if Israel reported none, or really low numbers of any kind of deaths associated with people getting .
Nick van Terheyden
My understanding is that the data says if you’ve had the vaccination, and to be clear, I don’t know whether you’re required to get both doses for this effect. But let’s assume that it’s both doses. In those instances, the incidence of any severe disease is 0%. That’s my understanding. Currently, there’s been nothing yet that’s emerged that says otherwise.
Fred Goldstein
Fantastic. So in closing, I guess my question was a bit ridiculous. Of course, I’m the one who gets to throw out the stupid questions. And you guys can can respond appropriately for them. So it’s always great doing that. And and I think you’re right, at the end of the day, while we go through this, though, we can’t we can’t forget that we’ve still got to keep doing those things of wearing our masks, distancing appropriately, and, and washing our hands. And really now you know, watching that indoor stuff, we’re seeing more and more about air handling in the area issue. So it’s important to really consider Do you need to go into that place? Or is there another way to solve that problem by by not doing that because remember to there are people working in those stores and their at risk, we’ve seen some statistics on grocery shopping on the people working in the grocery stores and the number of infections so it’s, it’s something we really don’t want to see happening. Anything else you’d like to add on herd immunity, as we finish this up?
Nick van Terheyden
I just I don’t want to call it a Mirage, I think we shouldn’t, you know, be despondent that we’re not going to achieve some level of, you know, widespread immunity. I would just caution that, you know, widespread immunity isn’t just the United States or the United Kingdom or a pick any country. This has to be worldwide for a variety of very good reasons, not just from a humanitarian standpoint. So this the onus is on us. That’s the beauty of all these various vaccines that are offering opportunity, especially the single dose without the cold storage or the cold chain requirements. So I think we’ll get there. It’s just, it’s going to take longer than anybody ever wants. But that’s been the story of COVID-19 the whole time that I’ve been involved with it, right.
Fred Goldstein
Well, thanks again, so much, Luis and Nick, another fantastic week. We’ll look forward to next week’s episode as well. And thanks for those who joined us this week. If you have any questions or comments, you can go to veilig health.com. We’d be happy to talk to you or follow up with you.
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