In this video, I want to answer your questions 
about the mRNA vaccines for SARS-CoV-2 or COVID19.

Once again, I've listed all 
my sources in the description,

so please check them out if you have doubts.

Question 1: Is this video sponsored 
by the pharmaceutical industry?

No, it wasn't sponsored by anyone. In fact,

so far, none of the Simply Explained videos 
have been sponsored. This one is no exception.

If you want to help and keep this channel 
independent, consider becoming a member.

Question 2: Why is a vaccine necessary?

As this viewer points out, our 
immune system is quite capable.

A vaccine is merely a helping 
hand, strengthening our immune

system so that fewer people need to 
be hospitalized and fewer people die.

According to John Hopkins University,

COVID19 has an observed case-fatality 
rate between 0,5% and 10%.

Let's take 2% as the average and assume 
that everyone on Earth got infected (7,7

billion people). We would be 
looking at 154 million deaths.

We can largely prevent these huge 
losses by developing vaccines.

So it makes a lot of sense to 
immunize as many people as we can.

Question 3: Will the vaccine 
prevent the virus from spreading?

That's not clear at the moment. After vaccination,

your body will start making a specific type of 
antibody that will circulate in your bloodstream.

However, the coronavirus enters 
our body mostly through our nose,

and here we have different types of 
antibodies. It's currently not known

how effective the vaccine's antibodies will be 
in this region. That means you won't get sick,

but you could still have virus particles 
in your nose, ready to spread to others.

That's also why vaccinated people can still test 
positive for the virus while not getting sick.

But there is hope. One study exposed 
vaccinated primates to the virus and

observed that they were able to clear the 
infection from their airways in a shorter time

than others. Indicating the vaccine 
reduced how long they were infectious.

Time will tell if the same holds up for humans.

Question 4: How is the efficacy 
of a vaccine determined? (The 95%)

The efficacy expresses the reduction of infections 
between vaccinated people and unvaccinated people.

Let's take a real phase 3 study as 
an example. In this case, there were

36,523 participants, half of which got 
the vaccine, the other half got a placebo.

Participants were closely monitored for 120 
days while keeping track of COVID19 infections.

In the group that received the vaccine, 8 people

eventually got COVID19. In the placebo 
group, there were a total of 162 cases.

The efficacy is then calculated by taking 
the difference between these groups and

dividing them by the number of cases in the 
unvaccinated group. This gives us a 95% efficacy.

This approach has been used many 
times before and is not new.

Question 5: mRNA vaccines have never been 
approved before. They are unsafe and rushed.

This is indeed the first time 
that mRNA vaccines are approved.

But that's not because they 
were rushed or corners were cut.

First up: mRNA technology isn't new. It's been 
researched and worked for more than 2 decades.

It's only now that the technology has 
matured enough for wide-spread use.

Secondly, we already studied other coronaviruses,

such as SARS, in great detail. These have similar 
spikes, so we could build upon this knowledge.

Thirdly, there was a lot of money available for 
research and production. The US alone invested

over 10 billion dollars into developing vaccines 
(Operation Warp Speed). This meant that companies

could conduct clinical trials in parallel while 
also ramping up manufacturing. Here's how vaccines

are traditionally developed, notice how it's 
very sequential, one step at a time. And this is

how the COVID19 vaccines were developed. You can 
see that many steps were conducted in parallel,

massively speeding up the process. Not skipping 
steps, but doing them at the same time.

And finally, regulatory 
agencies such as the FDA and EMA

gave priority to all studies related 
to COVID19. Companies were allowed to

periodically submit parts of their research 
for approval. This shortens the review times.

So, in summary: The vaccines were not 
rushed. They've been massively accelerated.

Question 6: Why can't we use traditional 
vaccine technologies instead of mRNA?

We can, and we do. There are many types of 
vaccines, and mRNA is just one of them. An

older and more commonly used technique is to use 
weakened viruses to boost your immune system.

I won't go too much into details since this 
video focuses primarily on mRNA. But here's

a handy overview of the types of vaccines and 
which company is working on them for COVID19.

Question 7: Can the mRNA in 
the vaccine alter my DNA?

No. Our DNA is contained in 
the nucleus of our cells.

While mRNA does enter our cells, 
it cannot enter the cell nucleus.

mRNA is naturally made by our body. When a cell 
needs a particular protein, the cell nucleus will

make a string of mRNA containing instructions and 
give it to the rest of the cell for execution.

So all we're doing with the vaccine, is 
temporarily give our cells other instructions.

Side fact: viruses that do "become a part of us"

are called retroviruses. The 
most commonly known one is HIV.

Question 8: What are the 
adjuvants? And are those dangerous?

No, they aren't dangerous. Adjuvants are 
used in almost all vaccines for the last 70

years. They signal your immune system to 
come to check out what is happing near

the place where you got injected with the vaccine.

That way, the immune system will more 
quickly notice the odd spikes in your body,

resulting in a more robust immune 
response with more antibodies.

Question 9: Why do some people 
get sick from the vaccine?

It's not uncommon for vaccines 
to have some side-effects,

and the ones for the coronavirus are no different. 
In this phase 3 study, side-effects were common

but mild. This included pain at the injection 
site, fever, tiredness, chills, and headaches.

It also found that participants had more 
side-effects from the second dose than the

first dose and that people older than 55 reported 
fewer side-effects than younger participants.

In summary: the mRNA vaccines 
are generally well tolerated.

In most cases, having some mild side-effects is 
better than actually having to fight off COVID19.

Question 10: The coronavirus is mutating. Will 
the vaccine protect me from those mutations?

We're talking about the UK 
and South-Africa mutations,

which allow the virus to spread more rapidly.

Early studies indicate that the mRNA 
vaccines might be just as effective

against the UK mutation. In this study, 
researchers took antibodies from people

that had received the 2 doses of their 
vaccine and exposed them to the mutation.

They found no reduction in neutralization 
activity. In other words: the mutated virus

did not develop a resistance against the 
antibodies produced by the vaccine shot.

The South-African mutation is a different story. 
That same study found a significant reduction in

neutralization activity, but they noted that the 
vaccine would still be effective. Some companies

are already working on tweaked versions of 
their vaccines to offer full protection.

However, we do have to be cautious 
with this data. It's an early study so

nothing conclusive just yet.

So that was it for this video. All of 
these answers are published on my website,

along with the sources and references that 
I've used. The link is in the description.

Thanks for watching. Consider 
subscribing and stay healthy!