Nov. 9, 2020 -- Pharmaceutical giant Pfizer says data from clinical trials shows its experimental coronavirus vaccine is 90% effective, and company leaders say they hope to seek emergency use authorization from the FDA this month.

The news about Pfizer’s vaccine sent the U.S. stock market soaring on Monday. Pfizer is one of several companies racing to develop a vaccine for the virus, which has killed more than 1.2 million people worldwide and upended life around the globe.

In a news release, the company said more than 43,000 people are enrolled in phase III of the clinical trials, with half of the people receiving the vaccine and half receiving a placebo. Ninety-four confirmed cases among participants were studied.

The company didn’t specify how many people who received the vaccine became infected, but said “the case split between vaccinated individuals and those who received the placebo indicates a vaccine efficacy rate above 90%, at 7 days after the second dose. This means that protection is achieved 28 days after the initiation of the vaccination, which consists of a 2-dose schedule.”

Participating in a COVID-19 Vaccine Clinical TrialWebMD's Chief Medical Officer, John Whyte, MD, speaks with Stella Sexton, a vaccine clinical trial participant, about her experience participating in the Inovio COVID-19 Vaccine Phase I Clinical Trial at Penn Medicine.674


JOHN WHYTE: Hey, everyone.

You're watching Coronavirus

in Context.

I'm Dr. John Whyte, Chief

Medical Officer at WebMD.

We're hearing a lot of talk

about the vaccine.

When might it be available?

Who's going to be eligible?

But what's it like to actually

participate in one of the trials

that are going on?

Well, today you're going to find


My guest is Stella, who's

participating in one

of these trials.

Stella, thanks for joining me.


thanks for having me on.

JOHN WHYTE: You know, let's

start off

with the obvious question.

Why did you decide to do it?

We don't have any treatment


And, you know, it's-- the trial

is not working.

Why did you do it?

STELLA SEXTON: Well, I, um, you

know, like everybody, I was

at home in April and May.

And I was, you know, following

the rules

and only leaving the house

for essentials.

And, um, some of the things

I was doing was taking care

of my elderly relatives, who

really, truly couldn't leave.

I have grandparents

in their 90s.

And, um, my-- my aunt's

in her 70s.

And so I was shopping for them,

obviously very

worried about them,

especially my grandparents, who

were in a retirement community

that did have about 16 or 17

COVID deaths.

So, um, you know, I was very

worried about that.

And I've always been

a big believer in vaccines.

And so one day

I just logged

on to my local health

system's website to look at the,

you know, case totals

for my county.

And I saw, um, COVID DNA trial,

a vaccine trial.

And I clicked on it.

And I thought, well, this would

be perfect for me.

It felt like, um, something more

that I could do beyond,

uh, you know, what everybody is


And, you know, obviously, I'm

not a health care professional

or anything like that.

I was at low risk of exposure

for myself.

And I'm healthy, so I sort of, I

guess, felt a duty

that because I have good health,

and I had the time and ability

to participate, that I--

I had to try.

JOHN WHYTE: Everybody wants

to know, what's it like?

How often do you have to go?

How many injections did you get?

Do you have any special, you

know, procedures?

What's kind

of the whole process?

Walk us through it.

What do you do?

STELLA SEXTON: Well, I can only

talk about my own experience.

I'm in the Inovio trial

through Penn Medicine.

And I'm a Phase I participant,

which means that I did not get

a placebo.

I actually got, um, a dose.

There were one of three doses

of the actual vaccine.

Um, so what worked for me may be

different than what somebody is

going through for a Phase III


But I will tell you that, um,

my safety

and my informed consent

were at the heart

of the whole process.

Um, I felt very well taken care


And I think, um,

so there's a-- there's a--

one appointment that's literally

just like an hour of them going

over your medical records

and consenting you.

It's a 22-page document.

And they talk about everything

that could happen, um,

everything that you need

to know,

and, you know, really

in plain language

make sure that you understand


The second visit was a full--


STELLA SEXTON: What's that?

JOHN WHYTE: Did that frighten

you, that 22 pages of what

could happen?

STELLA SEXTON: Um, it didn't

because I guess when I met, um,

when I met my research nurses

and I met, um, the-- the head

investigator, Dr. Tebas that I

felt so comfortable that they--

these were experts who have been

studying infectious diseases

for decades.

Um, you know, these researchers

were involved in trials

for hepatitis C treatments,

for HIV treatments.

And so when you meet people

who are obviously so caring,

and who are obviously so well

educated, and who obviously have

been doing it for such

a long time, um, it actually

gave me more confidence that we

would get a vaccine that worked,

and that they were taking

the safety very, very seriously.

So, no, I didn't.

I felt the opposite.

I felt, um, really confident,

because when you're

with true experts,

it makes you feel good.

JOHN WHYTE: So that's

the first time just--



[INAUDIBLE] over it.

STELLA SEXTON: There's blood


Oh, go ahead.

JOHN WHYTE: OK, blood work, OK.

STELLA SEXTON: Yeah, so there's

blood work, um, urinalysis.

I had to have an EKG.

I had a full, um, physical--

very thorough physical, and was

found to be in perfect health,

which was very--

very reassuring.

Um, and, of course, you have

to have a COVID test

and a COVID antibody test,

because they want people who

haven't ever been exposed.

Um, so I was negative for both

of those.

And then I went back.

And my-- my first injection

was June 8.

Um, and that was still very


I think there probably had only

been maybe a few hundred people

in the country at that point who

had had a COVID vaccine

of any kind.

So that was pretty

kind of exciting.

Um, and then, about close

to four weeks later was my--

my second injection.

Um, and then there's

various blood draws, uh, first

every 2 weeks up until about 12


And then it spaces out

to every 16 weeks

until we get out to a year.

JOHN WHYTE: Every two weeks,

you're going in for blood, blood



at the beginning,

for the first three months

or so.

And then it spaces out

after that, yeah.

JOHN WHYTE: OK, all right.


JOHN WHYTE: And how are you


STELLA SEXTON: Um, I feel fine.

I, um, had-- after the--

the first, uh, vaccination,

the-- the next day,

I felt a little bit of fatigue.

But when I say fatigue,

I mean I was still going

about my normal day,

taking care of my kids,

making dinner.

You know, I exercised.

I just, like, noticed, eh,

I'm kind of tired.

Like, and I went to bed

about an hour early.

So, I mean, if that's the worst

that happens

[CHUCKLES] that's not really

a big deal at all.

Um, and then

after the second vaccination,

I really didn't feel anything.

So I guess for me,

it would be the same as like,

mm, a mild reaction,

like how I felt after getting--

getting a flu vaccine sometimes.

JOHN WHYTE: So two shots.



Any special precautions, either

for you or your family members,

people that you--

STELLA SEXTON: Well, I can't--

so a big part of, um,

the-- the vaccine

is that, um, they're really just

trying to make you

immune to the spike protein.

Um, and they're using the DNA

of the spike protein that's been

synthesized to, um, stimulate

your-- it goes into your skin


and then stimulate

your immune system to make

antigens to that spike protein.

So, um, it doesn't contain any

of the actual virus.

Um, and therefore, it couldn't

make me contagious.

And it couldn't actually give me


So I felt very comfortable, um,

having the science explained

to me that I knew that I--

I couldn't endanger my family

in any way or anybody

that I came in contact with.

So for me, um, it's really just

a matter of following the same

rules that everybody else has

to follow right now,

because, um,

because I'm-- people ask me

a lot, well, wouldn't it help

them know if you got exposed,

and then you didn't get it?

And it's like, well, actually,

no, they don't want me to get

exposed, because they want, um,

when they look at my blood,

they want my immune system

to really only be showing

the effects

of the actual vaccine

and not any wild exposure


because that would actually

screw up their data.

So, um, so, no, I--

same-- same rules as everybody


JOHN WHYTE: Now, there's a lot

of discussion

that many people in the public

feel that the vaccine is being


They're not going to take

a vaccine, certainly not early

on, uh, if it does

become approved or authorized


What's your message

to those persons who are

skeptical about a COVID vaccine?


understand why they feel

that way, um, because, you know,

it is something that we--

we think

of vaccines taking a long time

to develop.

Um, but I would say that what I

learned in the process of being

a volunteer

is that there actually had been

a ton of research

on making coronavirus vaccines

for SARS and MERS

that occurred over the last, um,

two dec-- well,

at least for SARS,

over the last two decades.

And so there were really experts

in coronaviruses who had been

experimenting with this vaccine

for a long time.

Um, the company that made

my vaccine has a MERS vaccine

that's in, um, I think Phase III

trials in the Middle East.

And so because they had so much

experience with related

vaccines, it was, um, a fairly

quick process for them

to-- to pivot to, um, this new--

new coronavirus.

So I guess to me, I don't look

at it as a brand-new vaccine.

I look at it almost like how,

um, the flu vaccine has to be

changed a little bit every year,

um, because there's new flu


And this is sort of building

on that, that same thing.

So when I learned about how much

research has already gone

into creating

a coronavirus vaccine,

that made me feel more


And the second thing is I would

say, um, they're, you know,

they're working 12-hour days

to get people

through these trials

as fast as possible.

But they're not rushing

our safety.

My trial nurse, I can text him

at any time and say, oh, my arm

itches, like, you know,

or whatever.

And they have to write that


And that's very, um, you know,

they take all of that

very seriously.

So I don't think

that the science or the safety

is being compromised.

I think that we are benefiting

from, um, a whole body

of scientific knowledge

that most people didn't know

existed, um, that was there,

sort of ready--

ready to save us when

this coronavirus came out.

JOHN WHYTE: Now, you've been

documenting your journey

on Instagram.

Is that right?


Yes, I have.

Um, it's been a lot of fun.

And I've gotten a lot of really

positive feedback.

Um, you know, people ask really

good questions.

And, um, you know, I'm just

trying to help people understand

that, um, even though it seems

like a new process, that I--

I really have confidence

that it's a safe process.

Um, my trial, actually, the FDA

just held up the-- the--

the Phase III-- progression

of Phase III for my trial

because they had some questions

about the device that's used

to administer the vaccine.

And while that's frustrating at,

you know, on an emotional level,

I would love to see the vaccine

that I tested, you know,

be first.

It's not going to be first.

But, um, I think that, uh, that

shows that the FDA is being--

still being really careful.

Um, and they have put also

the brakes on the AstraZeneca

one while they look into things


That doesn't mean it's not going

to go forward.

There were no-- as far as I

understand, there were no, um,

serious reactions in my vaccine


But I-- I am seeing the FDA put

the brakes on things

and-- and still really review

and be careful.

So I would say, have confidence,

um, when it comes out

that if it's recommended

for your group,

that it's going to be OK to get


JOHN WHYTE: Well, Stella, I want

to thank you, first of all,

for participating in a trial,

and for coming on, and taking,

you know, our questions.

And we'll follow you on--

STELLA SEXTON: Absolutely.

JOHN WHYTE: And, uh--


JOHN WHYTE: Terrific.

And thank you for watching

Coronavirus in Context.

I'm Dr. John Whyte.

John Whyte, MD, MPH, Chief Medical Officer, WebMD.<br>Stella Sexton, Vaccine Clinical Trial Participant./delivery/aws/1c/1d/1c1da6ee-541b-3380-8b66-9148d765c93f/Sexton_100220_,4500k,2500k,1000k,750k,400k,.mp410/19/2020 12:00:0018001200Sexton_100220_1800x1200/webmd/consumer_assets/site_images/article_thumbnails/video/covid19-images/Sexton_100220_1800x1200.jpg091e9c5e820262d2

That 90% efficacy rate is far above the 50% benchmark the FDA says it wants to see in the vaccine.

“Today is a great day for science and humanity," Albert Bourla, PhD, Pfizer's chairman and chief executive, said in the release. "We are reaching this critical milestone in our vaccine development program at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen."

Pfizer’s partner in the vaccine is German company BioNTech. Ugur Sahin, MD, BioNTech co-founder and CEO, said in the release that researchers will keep collecting data until 164 confirmed cases have been studied.

“When we embarked on this journey 10 months ago this is what we aspired to achieve,” he said. “Especially today, while we are all in the midst of a second wave and many of us in lockdown, we appreciate even more how important this milestone is on our path towards ending this pandemic and for all of us to regain a sense of normality.”

In July, Pfizer signed a $1.95 billion contract with the U.S. government to deliver hundreds of millions of doses of a vaccine. The company and the U.S. Department of Health and Human Services said the vaccine would be free to Americans.

In its Monday news release, Pfizer said it expected to produce up to 50 million vaccine doses in 2020 and up to 1.3 billion doses in 2021.

The vaccine uses messenger RNA in different combinations to targeted antigens, with the goal of producing antibodies.

The news release said Pfizer hopes to finish collecting safety data in the third week of November so it can submit information for the emergency use authorization. The FDA insists that people who are in a clinical trial must be studied for 2 months after receiving their second dose of the vaccine.

The news release said the primary “endpoint” of the clinical trials is to evaluate confirmed cases 7 days after the second dose of the vaccine. Pfizer will also include a secondary endpoint of evaluating confirmed cases 14 days after the second dose.

“The companies believe that the addition of these secondary endpoints will help align data across all COVID-19 vaccine studies and allow for cross-trial learnings and comparisons between these novel vaccine platforms,” the release said.

WebMD Health News Brief


Pfizer: "Pfizer and BioNTech Announce Vaccine Candidate Against COVID-19 Achieved Success in First Interim Analysis From Phase 3 Study."

WebMD: “Pfizer Contracts With Feds for Vaccine Delivery.”


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