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

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

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so please check them out if you have doubts.

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

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

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

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

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Question 2: Why is a vaccine necessary?

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

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A vaccine is merely a helping 
hand, strengthening our immune

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

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According to John Hopkins University,

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

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

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

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We can largely prevent these huge 
losses by developing vaccines.

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

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

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

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

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

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

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

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

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

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

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

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

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Time will tell if the same holds up for humans.

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

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

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

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

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

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In the group that received the vaccine, 8 people

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

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

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

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

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

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

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

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

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

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Secondly, we already studied other coronaviruses,

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

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

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

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

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

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

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

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And finally, regulatory 
agencies such as the FDA and EMA

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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the place where you got injected with the vaccine.

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

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resulting in a more robust immune 
response with more antibodies.

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

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

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

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

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

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

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In summary: the mRNA vaccines 
are generally well tolerated.

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

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

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

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which allow the virus to spread more rapidly.

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

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

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

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

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

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

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

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

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

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nothing conclusive just yet.

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

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

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Thanks for watching. Consider 
subscribing and stay healthy!