Are You Protected Against the Delta Variant?

John Whyte, MD; Eric Topol, MD


July 28, 2021

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JOHN WHYTE: Welcome, everyone. I'm Dr. John Whyte, the chief medical officer at WebMD, and you're watching Coronavirus in Context. What is happening with the Delta variant? Are we all going to need boosters in the fall? Do we have to start wearing masks, whether or not we're vaccinated? So to help give us the answers, I've asked one of the best experts I know. Dr. Eric Topol is the editor-in-chief at Medscape, and is joining us from San Diego, California. Dr. Topol, welcome.

ERIC TOPOL: Great to be with you, John.

JOHN WHYTE: And I've got to start off with the Delta variant. You can't turn on the news without hearing about it. You and I have talked about variants before, how do we differentiate "scariants," in terms of what we need to worry about. I want to start off, though, by asking about vaccinated people. How concerned for those that are vaccinated be when it comes to the Delta variant?

ERIC TOPOL: Well, we'll see a report in The New England Journal today that indicates that vaccinated with the mRNA vaccine is very high protection. This is from Public Health England, a large sample, also comparing with Alpha variant. So the suppression or protection from infection is about 80% or better, and from severe illness, hospitalization or death, 95%, 96%. So the protection is excellent.

But because of the fact that we have 160 million Americans who have been fully vaccinated, we've got some people there who are going to get infected. Most of them will have mild illness, or even without symptoms, if they get tested. So this is something that I think, because of the math, in the denominators portion, so people are getting a skewed sample or sense of what's going on here. The vaccines we have are potent against Delta. They're not as good as prior versions of the virus for just preventing infections, but they're just as good for preventing severe illness.

JOHN WHYTE: All of them? You had some preliminary information preprint about the J&J vaccine, a different type of vaccine that we've talked about, not the mRNA, like Pfizer and Moderna. Still --


JOHN WHYTE: -- very good protection --

ERIC TOPOL: There's two --

JOHN WHYTE: -- or not as good?

ERIC TOPOL: Well, there's no -- yeah, John, there's no clinical effectiveness reports for J&J. There are two lab studies, you know, whereby they take serum and expose it in the lab to the variant from people who've been vaccinated. And in those two studies, both of them show, with the J&J vaccine, that the level of neutralizing antibodies was lower, but still above the threshold for protection.

And then in a preprint yesterday from NYU, it showed that it was less than the mRNA vaccines, but not contradicting the other one. So there's definitely some protection. The question is, is it good enough? And you know, I think this is something that's uncertain right now. We have a lot of anecdotes of people with J&J vaccines getting a breakthrough, but we don't have the data to cinch it yet. My suspicion is it's probably an issue, but I don't know for sure.

JOHN WHYTE: But Eric, how do we really know how many breakthrough infections there's been? CDC has stopped counting unless it's hospitalizations or deaths. So how do we make those accurate assessments?

ERIC TOPOL: Yeah, well, we have a real problem with lack of adequate tracking here. And we know that the more you'll test, like is being done at the Olympics right now or by the sports teams in certain places around the world, like the U.K. is testing fourfold more than us -- our testing has gone down as our outbreak has gone up, which is the wrong move. So there are more breakthroughs that are asymptomatic that are only getting picked up by testing.

But more importantly, there are people who are symptomatic, not getting tested. We want to sequence the virus when there's enough sample because it's not just a matter of defining Delta. We also want to stay ahead of this. There could be future variants of concern. So we are not doing this appropriately. And over a billion dollars was allocated to CDC to do this. And that was months ago, and nothing has happened.

JOHN WHYTE: Let's get to what listeners really want to know, Eric. They want to know: If I've been fully vaccinated, do I need to wear a mask, at least indoors? We saw that's happening not far from you in California, in Los Angeles, the recommendation to wear masks, irrespective of vaccination, inside. So it gets confusing. So what should listeners be doing? Let's assume they're fully vaccinated. Do they need to wear a mask at all? Do they need to change their behavior right now?

ERIC TOPOL: Right. Well, I mean, I think this is pretty clear. As you're alluding to the L.A. County, a very impressive surge of cases. And of course, all this was happening when the masks were abandoned in California. So I think the data is speaking to us that using a mask indoors if you're vaccinated is prudent, and especially if it's more than a very brief encounter. And the more people, the more vital the mask is needed, and the less ventilation. I call it the Delta stress test for a vaccine, right? That is, if you are vaccinated, you're in good shape, but this is a very contagious strain.

This is 1,000-fold more viral load, viral copies are hanging out in our nasal upper airway than in the Wuhan original strain. That's a lot more viral load. So the vaccines are great, but they are not perfect. And if we don't pass the stress test, if we don't wear the mask, that's not a good thing. And a mask is simple, and it helps, as does distancing and ventilation and, when you can, avoid indoors. If you're only with known vaccinated people, the risk is reduced. But it isn't certain because we still know it's possible that a vaccinated person could be in the presymptomatic phase, and still potentially be transmitting. It's very low chance, but it's still possible.

JOHN WHYTE: Because we thought a little while ago that vaccinated persons may not be spreading. We really don't know the answer for sure, do we?

ERIC TOPOL: Well, I think if they're symptomatic, they can.


ERIC TOPOL: The question is that, even in the couple of days before they develop symptoms, it looks like those who have had a substantial viral load, I don't see any reason why they couldn't transmit. It's just that this is rare, and you just don't know. So I think the smart thing is just, for the moment -- we're going to get through this Delta wave, it's a matter of weeks -- but for the moment, just assume kind of the worst-case scenario. Wear a mask indoors. You know, you're not going to regret it.

JOHN WHYTE: How concerned are you about what's happening in India? What's the preliminary data from Israel about the potential need for boosters? Again, we have some conflicting information. Pfizer says they're getting boosters ready for the fall. CDC and FDA says, hold on, there's no data that says we're going to need boosters. You and I have talked about it a couple months ago, before we had Delta variant. Now, we're going to hear about -- you mentioned on your Twitter handle Lambda variant, where we still need to have more data on. And I do recommend to everyone that they follow you on Twitter. How concerned are you about what's happening in other areas of the world that are going to impact what happens here?

ERIC TOPOL: Right. Well, you know, I think Delta is expressed in different countries very differently. So if you look at Indonesia and Russia and Bangladesh and South Africa, so many places, it's been ravaging these countries. They have very low vaccination rates, less than 20%, or even less than 15%, and so they're feeling the full brunt. Now, if you look at the U.K. and Portugal, Israel -- these are high-vaccination places -- they have markedly blunted the impact of Delta. But as you've alluded to, John, in some elderly people, many months passed when they got initially vaccinated. They have some breakthrough infections.

And it raises the question as to whether people of vulnerable, especially vulnerable people, might need a booster as we go forward. It seems likely in the elderly or people who are immunocompromised even now, of course, because they're not getting a third dose, and we know certain people, like organ transplant individuals, will benefit from a third dose. But will we need a booster for all people? That's still very uncertain.

And we haven't any new data, no evidence to make a judgment. I'm sure we will see that in the months ahead. But right now, as you know, John, the White House crew, administration, reviewed the data Pfizer had and said it wasn't compelling. And of course, that data hasn't been shared with us. So we'll see more of it. Eventually, we'll be able to make a call. But I'm thinking it's not an all thing, it's not everyone. But we'll see as evidence accrues whether that is the right sense of where we're headed.

JOHN WHYTE: Is there a danger of too many boosters perhaps selecting out certain variants, and then perhaps exposing yourself to something later on in terms of immune protection?

ERIC TOPOL: Yeah, I mean, I think the problem here with the booster we've just been talking about, it's just the same darn vaccine. And so all it does is just kind of rev up the immune response to the spike protein, but it doesn't have the multivalent vaccine specifically against Delta. And moreover, we know we could make vaccines that would knock out the entire SARS-CoV virus family, all the pan-coronavirus, and we're not pushing on that enough, because that could potentially be ready in the months ahead, too, and get us equipped to deal with any variant. So I'm disappointed that we're still going to be reusing the original vaccine, rather than shifting to one that would basically squash Delta, would be even more potent. I know that's in the works, and Delta is the most challenging version of the virus we've seen for sure, but I think we have to think bigger, and think about, you know, whatever Epsilon or Omega, we've got to think about --


ERIC TOPOL: -- those and just get -- yeah, we've got to get a vaccine ready for all things, all variants. And we can. I know we can do this.

JOHN WHYTE: What does September look like?

ERIC TOPOL: Hm. I'm actually right now thinking September, we'll be over this Delta hump.


ERIC TOPOL: If you watch India, they had almost no vaccines, and in about 2 months, they went from to a hellish, horrific situation to back to baseline. So basically what happens is it runs through the people it's going to run through, right? And most of them are unvaccinated. Some are vaccinated, but the vast majority unvaccinated. It doesn't, of course, hurt people with prior COVID as much. And I think people tend to forget that. If you've had COVID, you'd be better off to get one-dose vaccine, but at least you have some natural immunity. But it runs its course, it finds as many hosts as it can, and it goes through a population, like it will in the United States, and it's done for that time. I mean, it's still around, but it's not going to be -- yeah.

So then the question is, will another variant or another wave come through? We don't know yet. You know, Lambda doesn't look like it's going to be the one. There's nothing out there yet that looks like a Delta, you know, plus, a true worse than Delta. But the fact that it isn't contained in the world, it could be cultivating that next version. So I'm optimistic about September, but I don't know beyond that what's going to happen.

JOHN WHYTE: Well, I'll check in with you in September, as well, if not sooner. I always appreciate you taking the time. As I said at the beginning, I always turn to you when we have to find out what do we really need to know. So thank you, Dr. Topol.

ERIC TOPOL: Thanks, John. Always great to have a chance to talk with you.

This interview originally appeared on WebMD on July 28, 2021

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