Doctor Answers Vaccine Questions

I'm Dr. Paul Offit, pediatrician

and professor of pediatrics at the University

of Pennsylvania School of Medicine.

I'm here today to answer your questions from the internet.

This is vaccine support.

[upbeat music]

Happybrit17 asks, you do realize a lot

of what we get vaccinated for,

our immune system could just fight off naturally?

People love the word natural.

There's nothing good about a natural infection.

Mother nature's been trying

to kill us ever since we crawled out of the ocean into land.

I was a child of the 1950s.

I had measles, I had mumps, I had German measles,

I had chickenpox, and I survived every one

of those infections, but not everybody did.

Before there was a measles vaccine in 1963,

every year, 48,000 children would be hospitalized

with severe pneumonia or dehydration

or inflammation of the brain,

which could leave those children then blind or deaf.

Mumps was the most common cause

of acquired deafness, rubella or German measles,

when it affected pregnant women would cause

about 20,000 cases of congenital birth defects every year,

manifested as blindness, deafness,

or permanent heart defects.

I was lucky I wasn't one of those 75 to a hundred children

who died every year from chickenpox

or the 10,000 who were hospitalized.

So while many of us are able

to survive a natural infection, some aren't.

In fact, I actually don't like the term natural immunity.

I prefer the term survivor immunity.

Ravo93 asks,

has herd immunity ever been achieved without a vaccine?

Herd immunity means a critical percentage of people

around you have been vaccinated

and are protected so much so that's very hard for that virus

or bacteria to get to you.

Also remember, millions

of people in this country can't be vaccinated

because they're immunocompromised.

They can't be vaccinated because they have cancer.

They depend on us to protect them and they count.

So herd immunity is important, but has a virus

or bacteria ever been eliminated by natural infection?

No, smallpox, which was estimated

to kill about 500 million people.

It was never eliminated until there was a vaccine.

Polio in the United States would every year cause tens

of thousands of children to be paralyzed

and thousands to die.

That was eliminated in 1979 because of a vaccine.

So only vaccines have the capacity

to eliminate these viruses.

Herd immunity won't do it.

In 2014, 2015, there was a measles outbreak

that started in Southern California

that then spread to other states.

It affected hundreds of people.

Richard Pan was a state senator in California

that was embarrassed

that his state had been the epicenter of this outbreak.

So he wanted to eliminate the philosophical exemption

to vaccination in a state

that never had a religious exemption.

If he was successful, that would've meant

that the only exemptions

in California were medical exemptions.

The anti-vaccine activists hated this,

and they showed up in droves to cry

this particular attempt

to eliminate the philosophical exemption for vaccination.

There was a little boy who showed up at those meetings.

He had leukemia, and so he would stand up at those meetings

and they would have to put him on a stool

because he didn't reach the microphone

and he would say his name, I have leukemia.

I can't be vaccinated, I depend on you to protect me.

Don't I count?

And he stared right at these anti-vaccine activists

when he said it, he was a brave little boy

and he had everything to do with how it came to be

that California now only has a medical exemption

to vaccinations.

Only the children are brave and women,

children or women, forget us.

Leftymatty asks, how do you deal with anti-vaccine parents?

First of all, I think it's reasonable to be skeptical

of anything you put into your bodies, including vaccines.

I think I would divide this group up into two.

One are parents who just are scared.

They read things that are frightening on the internet

or vaccines causing cancer

or heart disease or autoimmune disease, is that possible?

And those people have questions

and you just try the best you can to answer those questions

and not to in any sense deny their fear.

Their fear is real.

And you can't sort of deny it

by just saying, well, that's silly.

You have to accept that that is a real fear

and that you have to try

and provide them with information that calms that fear down.

The second group of parents,

and this is a much smaller crowd, are people

who just think there's a conspiracy to sell vaccines.

They think you're a part of that conspiracy

and there's really nothing you can say

to make them feel better about this

because they think you're just an instrument

for the pharmaceutical industry.

I usually don't spend a lot of time talking to those folks

because there's no point wasting their time and mine.

Kurko asks, how was the smallpox vaccination campaign

so effective that the disease was completely eradicated

when the smallpox vaccine had very real side effects?

So there are two different kinds of viruses.

There's viruses

that have short incubation periods

like two days, three days, four days.

SARS-CoV-2, the cause of COVID, rotavirus, influenza,

respiratory syncytial virus has short incubation periods.

Then there's the long incubation period diseases,

German measles or chickenpox or smallpox.

You can eliminate those diseases.

You don't need antibodies in the circulation

at the time you're exposed.

All you need is memory cells, which have plenty of time

to become activated and make antibodies well

before you get sick because it's a long incubation period.

So you can eliminate smallpox, which we did by 1980.

You can eliminate polio from this country,

which we did by 1979.

You can eliminate measles,

which we did from this country by 2000.

You'll never eliminate rotavirus or SARS-CoV-2

or RSV, respiratory syncytial virus, or flu

because they are short incubation period diseases.

That's one critical difference.

And I think we could have done a better job

of explaining that actually regarding the COVID vaccine

because while COVID vaccine will protect

against severe disease, which is the goal,

it's never gonna protect against mild

or moderate disease for long.

So the smallpox vaccine certainly had real side effects

and smallpox vaccine could

occasionally cause fatal side effects.

It's true, but smallpox was a feared

and devastating illness.

One of the reasons we were able

to eliminate it is there's no such thing

as asymptomatic smallpox.

Everybody who has smallpox will have lesions

or blisters on their face.

And with that you can kind of put a moat around the virus,

meaning not only the person who has it,

but the person who they had contact with.

And that's why you can essentially eliminate that.

Ummuau asks, to the doctors on the timeline,

what is the purpose of all the vaccines babies are given?

Polio, rotavirus, et cetera.

Vaccines are given to prevent diseases that cause children

to suffer or be hospitalized or die.

And when they are introduced, those diseases are rampant.

Polio, for example, in the 1950s caused as many

as 58,000 children to be paralyzed

and 1800 to die every year.

Because of the polio vaccine,

we eliminated polio in 1979.

So you could ask, why do I still need this vaccine?

Polio's gone from this country.

Well, it's not gone from this world

and if you choose to lower immunization rates,

it'll come back.

And that happened in 2022

to a 27-year-old man in Rockland County, New York

who never left this country who was paralyzed by polio.

And that virus that paralyzed him really only paralyzes one

in every 2,000 people it infects.

So he was the tip of a much bigger iceberg,

and indeed you found the virus

that infected him in wastewater samples where he lived,

which is in Rockland County, New York.

You found it in surrounding counties.

And if you looked in Philadelphia or you looked in Chicago

and looked in the wastewater there,

you would also find this virus.

We eliminated measles from the United States

by the year 2000, eliminated it, gone.

Nonetheless,

this past year we've had thousands of cases of measles.

We've had three people die, including two children die.

So I think if we let our guard down,

these viruses will come back.

I think we ask a lot of parents in this country,

we ask them to give vaccines

to prevent 14 different diseases

in the first few years of life.

That can mean as many as five shots at one time.

To prevent diseases most people don't see

using biological fluids most people don't understand.

I think that people are pushing back

against vaccine makes sense.

I'm a child of the fifties.

I had many of these disease, I had measles, I had mumps.

And for about six weeks I was in a polio ward

in suburban Baltimore.

So I know what these diseases look like,

but my children are children of the nineties.

They don't see these diseases

and they didn't grow up with these diseases.

And the same is true for young physicians.

And so I think we have to be much better

at compelling people for why it is still important

to get vaccines because if we don't,

these diseases will come back,

as we're seeing with measles today.

A Reddit user asks

who came up with the idea that vaccines could cause autism?

There was a British gastroenterologist

named Andrew Wakefield who published a paper

in a respected medical journal claiming that children

who were otherwise healthy got a combination

of measles, mumps, rubella, MMR vaccine

and that they developed autism.

Now, it wasn't really a study, it was really a case series

of eight children who had received the vaccine

and then developed signs and symptoms of autism.

So he hypothesized that maybe the vaccine had done it.

Now, he might as well have published a study

of eight children who had eaten

recently a peanut butter and jelly sandwich

and then developed signs and symptoms of autism

because there really was no biological mechanism

that made sense for why that would be true.

Now since that paper came out in 1998,

there have been 24 separate studies costing millions

and millions of dollars trying to answer the question,

were you at greater risk if you had gotten the MMR vaccine

of developing autism than if you never got that vaccine?

And all the studies have shown exactly the same thing.

The MMR vaccine doesn't cause autism, but he scared people.

And while it's very easy to scare people,

it's hard to unscare them.

And I think still that false notion

that vaccines could cause autism exists.

So Kdsburner asks, why do we need boosters

for some vaccines and not others?

Well, some vaccines are better able

to induce an immune response more quickly.

The measles vaccine, which was first invented in 1963,

worked very well actually as a single dose vaccine.

There were outbreaks in the late 1980s

that resulted in hospitalizations, about 160 deaths

and that necessitated then a second dose.

But if you looked at those outbreaks,

they were in people who never got vaccinated.

I think if we just had had a single dose

and everybody got it, we'd have been fine.

Other vaccines, for example, like the hepatitis B vaccine

are just a single protein.

And with that, you really need more doses

to induce an immune response.

So it really depends on the nature of the vaccine

to determine whether or not you need a booster or not.

Bzeurunkl asks, where are vaccine memories stored?

When you get a vaccine, you make antibodies

and those antibodies are in your circulation,

your bloodstream, and they're there to protect you,

when you're exposed then to a virus or a bacteria.

Usually four to six months later,

those antibodies in your bloodstream fade,

but you have memory cells called B cells, for example,

that can make antibodies when stimulated.

So when you're then exposed,

even though the antibodies may not be there

in your circulation, you still have these memory cells

that often are lifelong,

those memory cells become activated.

They make antibodies that can protect you.

So memory is really what protects us.

Funbox304 asks, vaccination, is postponing bad?

It's hard to watch a child get laid down

and get five shots at once.

And it's easy to understand how a parent could say,

I'm happy with getting vaccinated,

but just don't give them all at one time.

Maybe have one or two and we'll just delay it

and space them out.

All delaying a vaccine does is it increases the period

of time during which you're susceptible to infections.

Some parents could argue, but isn't it more stressful

to get five shots than say just to get one shot?

And the answer is no, actually.

There were studies done showing

that if you look at cortisol secretion in a child

that gets one shot versus two shots or more, it's the same.

Or said another way, you're maximally stressed out

at one shot, so why just have more visits

and delay it when you're not in any way helping a child?

So Cruxsux, asks, where does the medicine go

when you get an injection or a shot?

So when you get an injection, say with the measles vaccine,

what happens is the virus reproduces itself

and then travels to a local draining lymph node

under your arm, for example.

And there it's taken up by immune cells that process it

and present it to the immune system

to induce an immune response.

Thebroccolioffensive asks,

ah yes, the old y'all gonna get microchipped statement.

So you can inject microchips,

but microchips are too big to fit through a needle

that is used for vaccines.

And there's a picture here that clearly shows the size

of a microchip needle

and compares it to the size of a vaccine needle,

and you can see that it's dramatically different.

Apatheticonion asks, why does administering a vaccine

to a sick person not cure an existing infection?

Vaccines work to prevent infection, not treat it.

Now there are some vaccines that can be given

after someone's been exposed to the virus.

Some viruses have very long incubation periods.

Incubation period means from the time

when you're first exposed to the virus

to when you develop symptoms.

So for example, rabies,

once you've already developed symptoms,

there really is no vaccine

that then prevents further progression of that disease.

When you're infected, the virus reproduces itself more

and more and more.

In response, your body makes an immune response,

and so as the body makes an immune response,

the virus starts to reproduce itself less and less.

It's the immune response that causes the symptoms,

so that by the time you already have those symptoms,

it's really too late to do anything

about the virus to make a difference.

Parallelpain asks, vaccines predate the germ theory.

So how did doctors think vaccines worked?

So the germ theory was born in the late 1800s

when we realized that specific bacteria,

in this case anthrax could cause a specific disease.

Robert Koch was the name of the person who did that.

But nonetheless, if you look at the smallpox vaccine,

that was developed before the germ theory.

So how did Edward Jenner develop a smallpox vaccine

when he didn't know anything about the germ theory?

It was really just pure phenomenology.

He noted that women

who milk cows would get these blisters on their hands.

He thought, okay,

well if these milk maids are getting blisters

on their hands and then they're not getting severe smallpox,

then I'm gonna just take that blister, drain it,

and then inoculate it into people

and see if it protects them as well.

Edward Jenner would take a drop of this puss from someone

who had cowpox and then he would take the needle

and he would inject that puss under the skin.

Essentially, Jenner's vaccine,

which developed in 1798 is pretty much

the same smallpox vaccine that we use up until today.

We eliminated smallpox from the world by the year 1980.

This was a virus that killed 500 million people.

About one out of every three people who were infected

with smallpox died, and many were left blind.

Whitelightning asks, have been told

that the mRNA vaccine leaves the body completely

after two weeks, leaving antibodies.

My question is, where does it go?

Do you pee it out and it ends up in the water supply?

Just curious.

The COVID vaccine was a messenger RNA vaccine.

So we all have messenger RNA in our bodies.

Those messenger RNA strands are used to make the enzymes

and proteins necessary for life.

Your messenger RNA is then translated to these proteins

and within a few days the messenger RNA disintegrates

and ultimately leaves the body primarily through the urine.

Diviningdad asks, why do so many people claim

that the COVID vaccine killed people?

The mRNA COVID vaccines could cause rarely

about one in 50,000, something called myocarditis,

which is inflammation of the heart muscle.

It was transient, it was self resolving, it was short-lived.

The virus itself, so-called SARS-CoV-2 virus

could cause severe and occasionally fatal myocarditis.

So that wasn't the vaccine.

I think people understandably have a distrust

of the pharmaceutical industry, which has acted at times,

unethically and aggressively and illegally,

but there is no hiding in the world of vaccines.

If a pharmaceutical company, for example, misrepresented

or omitted data to the FDA about their vaccine,

you very quickly would know that

because of something called the Vaccine Safety Data Link,

which is linked computerized medical record system

that involves about 10% of the US population,

about 500,000 children.

So when a vaccine rolls out,

you very quickly know who's gotten a vaccine and who hasn't.

So if there is a side effect that's rare,

you'll know it and you'll know it within weeks.

Lostonofpluto asks,

the flu vaccine has been available as a nasal mist

for some time now, but what's stopping other vaccines

from becoming available via this method?

It's certainly easiest to give vaccines as a shot.

A flu mist is a vaccine that's given as a nasal spray.

There are acids and proteases in the upper respiratory tract

that can break down viruses.

So it's not easy, the only oral vaccines that we had were

for the polio vaccine, but polio is an intestinal virus.

So polio normally reproduces itself in the intestine.

It lives in sewage, therefore you can just give it by mouth

and it survives the acids in the stomach.

Same thing with rotavirus,

rotavirus is another intestinal virus,

and so you can give that vaccine by mouth

and that vaccine has been given by mouth since 2006.

Paxtecum8 asks, new question about virus,

why there is no vaccine for HIV

or any sexually transmitted disease?

So there are two sexually transmitted diseases

for which there are vaccines.

One is the human papillomavirus vaccine,

which is sexually transmitted and can cause anal, genital

and head and neck and cervical cancers.

And then the other sexually transmitted disease

is hepatitis B virus.

That vaccine has been around since 1981.

The problem with human immunodeficiency virus is

it continues to mutate in your body

during a single infection.

So although you make antibodies

to human immunodeficiency virus

that could neutralize the virus,

the virus is constantly moving away from your immune system.

So even though HIV was recognized as the cause

of AIDS in the early 1980s

and the hope was that we would be able

to make a vaccine within a few years,

it's been more than 40 years

and we haven't been able to make a vaccine.

That is a moving target

and that's why HIV has been so hard to conquer.

Circleofmamas asks, why is so much aluminum

in vaccines okay?

I don't understand how this gets a pass.

Aluminum adjuvants have been in vaccines since 1926.

By having an adjuvant in a vaccine that allows you

to give fewer doses of that vaccine

and lesser quantities of the vaccine itself.

And it's necessary for certain vaccines

like the hepatitis B vaccine.

So there's seven different vaccines

that are given to infants and young children

that contain aluminum adjuvants.

Aluminum is the third most abundant element

on the Earth's surface.

We encounter and manage far more aluminum in the food

that you eat, in the water that you drink

than you ever get from vaccines.

In fact, if you look in the blood of people

who receive vaccines, you can't in any way correlate that

with their vaccine history.

They still have roughly the same amount

of aluminum in their blood and in their hair.

So assuming you live on this planet, you're gonna be exposed

to far more aluminum from living here and eating the food

and drinking the water

than you would ever get from a vaccine.

Iamheretoboreyou asks, so did the SARS-CoV-2

or COVID virus leak from a lab or not?

The SARS-CoV-2 virus was an animal to human spillover event

that occurred in the southwestern section

of the Huanan Wholesale Seafood Market.

The reason that this notion that a lab leak exists is

because the Chinese government basically killed

all the animals in that seafood market very early on.

Plus they didn't allow for international scientists to come

and evaluate what was going on.

Now, SARS-1 on the other hand, which also was an animal

to human spillover event that occurred in Foshan, China,

they didn't kill the animals then.

So people could come in and see that,

for example, raccoon dogs could be

that intermediary between a bat

and a human that allowed the virus then

to enter the human population.

But the reason we know is because,

although they killed the animals,

there were still genetic evidence

for that virus in that stall.

All the early cases really emanated from that central stall

and then spread from there.

The Wuhan Institute of Virology was nine miles away

and had nothing to do with this virus spreading.

The reason that this has survived is more interesting,

it's more compelling that there were evil doers

and it also makes it seem like it's more controllable

because probably 70% of the viruses and bacteria

that were infected with were animal

to human spillover events, which is much less controllable.

And in fact, now with sort of deforestation,

we live in closer and closer association

to bats than we ever did before.

Kingofdamnnation asks,

is it true that you get 72 vaccines?

No, I'm not sure where the number 72 came from.

Someone made it up.

You get vaccines to prevent 17 different diseases

in the first 18 years of life.

That can mean typically as many as 33 inoculations

during that period of time, depending on sort of your uptake

of COVID vaccine or yearly flu vaccines.

Merendi1 asks, what does it take to develop a vaccine

and why does it take so long?

If you see a virus, for example, that's circulating,

that's causing serious disease in this country,

in this world, now you know

that this is something worthy of preventing.

So the first thing you do is you work

with experimental animals like mice

and you have an idea for how you wanna make that vaccine.

Let's say you want to take the virus and weaken it,

or you wanna take the virus and kill it.

You're trying your strategy in these experimental animals

to see whether it works.

Then you go to phase one studies

where now you try your strategy in people to see whether

or not it seems to induce an immune response

which is protective

and that at least it's safe in a few dozen people.

Okay, so now you think you've got it.

You think you know the number of doses,

you think you've got the right strategy.

You think you've got the right buffering agent,

the right stabilizing agent.

And so you go to phase two studies,

which usually involves hundreds of people.

If that works and you found at this point

that at least the vaccine doesn't cause common side effects,

then you go to the definitive trial,

the so-called phase three trial,

which is a prospective placebo controlled trial,

typically of tens of thousands of people

to show that the vaccine works

and that it doesn't have any uncommon side effects.

Then you submit that to the Food and Drug Administration,

which usually takes about 10 months to license it.

Then that goes to the CDC, which then recommends the vaccine

or doesn't, and that takes time.

So I was fortunate enough to be part

of the team at Children's Hospital of Philadelphia

that created the Rotavirus vaccine.

We did all of that and it took roughly 26 years to do it.

How come it took 26 years to make the Rotavirus vaccine,

but it took only 11 months to make a COVID vaccine?

And the answer is Operation Warp Speed.

It took the risks out of it for pharmaceutical companies.

Now you could do phase one, phase two, phase three trials.

You could build a building,

you could make hundreds of millions of doses,

and if it didn't work,

then you could just throw it all away

at no cost to the company.

That doesn't work that way normally,

and that's why it was so fast.

Frankly, I think Operation Warp Speed was one

of the greatest medical

or scientific achievements in my lifetime.

Orneryblonde asks, what are vaccination schedules based on?

Usually vaccines are given

before someone would likely be infected

with a virus or bacteria.

So children are inoculated at two months, four months,

or six months of age to protect them against diseases

that would likely occur between six months

and 24 months of age.

So for example, the human papillomavirus vaccine,

which is designed to protect against

a sexually transmitted disease, isn't given in infancy.

It's given in adolescence at a time

before people are likely to have sex.

Geeksumsme asks, curious minds want to know,

how does getting multiple vaccines

at once affect the efficacy?

When a vaccine is added to the immunization schedule,

you have to prove that if it's going to be added

to the schedule, it doesn't interfere with existing vaccines

and that those existing vaccines don't interfere

with your vaccine.

There are hundreds of these studies,

they're called concomitant use studies,

and so that's how you know.

A Reddit user asks, when did vaccines become

a political talking point and who started it?

Public health is to some extent always political

because it requires resources,

but it doesn't have to be partisan.

I think in the first year of the COVID pandemic,

we didn't have anything.

We didn't have antivirals till October.

We didn't have monoclonal antibodies till November.

We didn't have vaccines till December to try

and prevent a virus that was being spread asymptomatically

and could kill hundreds or thousands of people a day.

So all we could do was limit human to human contact.

So what do we do?

We shut our schools, we closed businesses,

we restricted travel, quarantine,

social distance, tested, tested, tested.

And I think that was seen by a segment of the population

as massive government overreach

and at some level, reasonably,

I think we did shut our schools too long.

I think we closed business too long

and it was done in a dictatorial top-down fashion.

I think we should have involved the business community,

involved the educational community in those decisions,

especially for children who were special needs children

who probably suffered this the most.

Then the following year when we had a vaccine,

you couldn't go anywhere without your vaccine card

and that too was seen as massive political overreach.

And I think with that we leaned

into the libertarian left hook

and I think we're feeling the punch

of that libertarian left hook now.

When RFK Junior says that he is in the position he's in

because of the COVID pandemic, I think he's right

because with the COVID pandemic there was a segment

of this population that was really angry.

He represents that anger.

He represents that disdain

for these public health and government agencies.

Razorbeamz asks, is RFK Jr. anti-vaccine

or has he ever been?

RFK Jr. has been a virulent anti-vaccine activist,

science denialist and conspiracy theorist

for about 20 years.

For the last 10 years, he's been paid hundreds of thousands

of dollars by an anti-vaccine group

called Children's Health Defense.

And by anti-vaccine, I mean someone

who consistently puts out misinformation about vaccines

that causes people to put themselves

or their family members in harm's way.

For 20 years he's been shouting from the sidelines,

putting out his misinformation about vaccines,

scaring people about vaccines,

and now he's Secretary of Health and Human Services

and he's making public policy.

As a consequence, what we are seeing is

that vaccines are gonna become less available,

less affordable, and more feared.

2025 has been a rough year.

We've had more measles cases in this country

than we've had in the last 30 years.

We've had three people die from measles this year.

We've had about 290 children die of influenza this year.

We haven't seen a number

that big since the Influenza Pandemic in 2009.

And what has Robert F. Kennedy Jr. done about this?

Not a thing.

He could use his bully pulpit, his famous name

and stand up and say, vaccinate your children.

But he doesn't because he doesn't believe in vaccines.

He believes that vaccines have

merely replaced infectious diseases with chronic diseases

and he will do everything he can to try

and lessen vaccine uptake in this country.

All right, that's it, that's all the questions.

Hope you learned something, until next time.

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