Aug. 2, 2021 – Easing of pandemic-era restrictions on masking and social distancing may increase the chances a vaccine-resistant strain of the coronavirus emerges, according to a new study published in Scientific Reports.

Although vaccination is the best strategy to control viral spread, we must also change our behavior and mindset to stay ahead of vaccine-resistant strains, according to the four authors of the report.

Are You Protected Against the Delta Variant?WebMD's Chief Medical Officer, John Whyte, MD, speaks with Eric Topol, MD, Executive VP, Scripps Research & Editor-in-Chief, Medscape, about the COVID-19 Delta variant. 808


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


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.


to be with you, John.


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 "scariance,"

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


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


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 JandJ vaccine,

a different type of vaccine

that we've talked about,

not the mRNA,

like Pfizer and Moderna.



JOHN WHYTE: --very good


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 JandJ. 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


And in those two studies,

both of them show, with the JandJ


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


We have a lot of anecdotes

of people with JandJ 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.


how do we really know how many

breakthrough infections there's


CDC has stopped counting

unless it's hospitalizations

or deaths.

So how do we make those accurate


ERIC TOPOL: Yeah, well, we have

a real problem with lack

of adequate tracking here.

And we know that the more you'll


like is being done

at the Olympics

right now or by the sports teams

in certain places

around the world,

like the UK 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,


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


Do they need to wear a mask

at all?

Do they need to change

their behavior right now?


Well, I mean, I think this is

pretty clear.

As you're alluding to the LA

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


This is 1,000-fold more viral

load, viral copies are hanging

out in our nasal upper airway

than in the Wuhan original


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


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?


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 UK

and Portugal, Israel--

these are high vaccination


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


And it raises the question

as to whether people

of vulnerable, especially

vulnerable people

might need a booster as we go


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


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


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


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


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?


I'm actually right now thinking


we'll be over this delta hump.


ERIC TOPOL: If you watch India,

they had almost no vaccines,

and in about two 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,


And most of them

are unvaccinated.

Some are vaccinated,

but the vast majority


It doesn't, of course,

hurt people with prior COVID as


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


and it's done for that time.

I mean, it's still around,

but it's not going to be--


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.

John Whyte, MD, MPH, Chief Medical Officer, WebMD.<br>Eric Topol, MD, Executive VP, Scripps Research & Editor-in-Chief, Medscape./delivery/aws/0d/0d/0d0d1655-299e-3d4a-a3ce-33448fe359f9/Topol_072121_v4_,4500k,2500k,1000k,750k,400k,.mp407/28/2021 12:00:0018001200Topol_072121_1800x1200/webmd/consumer_assets/site_images/article_thumbnails/video/covid19-images/Topol_072121_1800x1200.jpg091e9c5e821fe81a

"We have become accustomed to thinking of the pandemic from the point of view of epidemiology, and advised to reduce transmission and the number of people getting sick and the death rate,” co-author Fyodor Kondrashov, PhD, an evolutionary biologist at the Institute of Science and Technology in Austria, said at a press briefing Thursday. “As the pandemic spreads across years, there will be a new dimension to our thinking, both for policymakers and the public. And that's the evolutionary perspective."

The coming "change of mentality" that Kondrashov foresees should reassure people that masking and social distancing even after being vaccinated is vital.

"It decreases the possibility that a vaccine-resistant strain is running around. We're not just trying to prevent the spread, but the evolution of novel variants, which are so rare at this point that we haven't yet identified them," he said.

The researchers simulated the probability that a vaccine-resistant strain will emerge in a population of 10 million individuals over 3 years, with vaccinations beginning after the first year. For eight scenarios, rates of infection, recovery, death, vaccination, and mutation, and the percentage of individuals with resistant viral strains were factors in the model.

The model also simulated waves of low and high transmission, similar to the effects of large-scale interventions such as lockdowns.

Three Factors

The study showed that three factors increase the probability of a vaccine-resistant strain taking hold:

  • Slow rates of vaccination.
  • High number of infected individuals.
  • Faster mutation rate.

These factors, Rello said, are obvious to some degree.

"Every infected individual is like a mini-bioreactor, increasing the risk that mutations will appear that will endow the virus with the property of avoiding the immune system primed by a vaccine," he said.

Not as obvious, Rello added, is that when most people are vaccinated, a vaccine-resistant strain has an advantage over the original strain and spreads faster.

But we can stop it, he said.

"Our model shows that if at the time a vaccine campaign is close to finishing and nonpharmacological interventions are maintained, then there's a chance to completely remove the vaccine-resistant mutations from the virus population,” he said.

In scenarios where a resistant strain became established, resistance initially emerged after about 60% of the population had been vaccinated. That makes nonpharmaceutical interventions such as masking and social distancing vitally important. Just under 50% of the U.S. population over the age of 12 has been fully vaccinated, according to the CDC.

A ‘Powerful Force’

"We hope for the best, that vaccine resistance has not developed, but caution that evolution is a very powerful force, and maintaining some precautions during vaccination may help to control that evolution," said Kondrashov.

He's pessimistic because many countries are still having difficulty accessing vaccines, and vaccine efficacy wanes slightly over time. The authors warn that "the emergence of a partially or fully vaccine-resistant strain and its eventual establishment appears inevitable."

The worst-case scenario is familiar to population biologists: rounds of "vaccine development playing catch up in the evolutionary arms race against novel strains," the authors write.