Episode #16 - COVID-19 - How do vaccines work?
12 December 2020 | Science conversation
Podcast
Transcript
Vismita Gupta-Smith
How do vaccines work to protect us? And what are the different
approaches that we are hearing about now for vaccines? Hello and welcome to Science in 5. I’m Vismita Gupta-Smith and this
is WHO’s conversations in science. Explaining this and more today is WHO’s Dr Katherine
O’Brien. Welcome, Kate.
Dr Katherine O’Brien
Thank you so much.
Vismita Gupta-Smith
Kate, explain to me how vaccines work with our body to protect us.
Dr Katherine O’Brien
Vaccines, what they do is they are a part of the germ that our
body can recognize and develop an immune response to so that the next time that
we see the real germ, there are already fighters in our body to protect us
against the infection. For coronavirus, we know that it's a part of the outside
of the coronavirus, the spike
protein, is the part that if we have fighters against the spike protein, we
will have a much lower chance of getting disease or getting serious disease
from coronavirus. And the
fighters that I'm speaking about, those are called antibodies. It's the part of
our immune system that is the part that can attack that particular part of the
virus.
Vismita Gupta-Smith
So, we're hearing about different terms like mRNA, and different
approaches. Explain that, please.
Dr Katherine O’Brien
So, all of the vaccines are ultimately trying to do one thing: they’re
trying to get that part of the virus, the spike protein that I just spoke
about, into the body so that our immune system can develop antibodies against
the spike protein. And there are two big categories of approaches to do that.
The first approach is just put in the vaccine part of the spike protein or the
spike protein itself. And the second category is, give the instructions for how
to make the spike protein and let the body produce the spike protein. In the
first group, where we actually give part of the spike protein, this is how the
vaccines that we have for lots of other diseases work. And sometimes, the
vaccine is developed so that it has just that part of the germ in it, in this
case the spike protein. And in other cases, what is given is highly weakened or
even killed version of the virus that still has the spike protein on it. So,
there are different strategies within that first category of giving the spike
protein. In all cases, it is so weakened the particles that are given that they
don't cause disease in us. So, you're not going to get disease from the
vaccines that are given even if it’s a weakened part of the of the germ. The second
category, where we're giving the instructions to the body on how to make the
spike protein, this is a new strategy that's being used. And it's a really
important new strategy because we can develop vaccines very quickly, a much
more efficient way of developing vaccines and using the body's own ability to
produce proteins is a really powerful tool.
Vismita Gupta-Smith
Kate, when we hear about vaccines developed from parts of
viruses, people may have questions about safety. Speak to us about safety of
these vaccines.
Dr Katherine O’Brien
Our immune systems are incredibly powerful. On a daily basis, a
weekly basis, a monthly basis, our immune systems are seeing all kinds of
viruses that come at us in our noses, in our mouths, in our intestinal track on
our hands. What's out there and readying itself for when it's exposed to
something that could be causing disease. What the vaccines do is they provide
to the immune system a small part of a germ that we know can cause disease. And
it's training the immune system so that it is completely ready when it actually
sees that particular germ. The vaccines that we have that have been used in
hundreds of billions of doses for decades, and in fact for centuries for some
of the vaccines, have been studied, evaluated for safety and for the impact
that they have. And, we have a safety system for all vaccines that is
constantly looking at the information about the performance of the vaccines and
picking up any issue around safety that might arise in the future. So, I think
we can be really well assured that we have a very strong system in place to both
look at safety, assure safety, before a vaccine is authorized for use and will
continue to monitor safety even after it is deployed for widespread use.
Vismita Gupta-Smith
There you have it, Dr. Katherine, O'Brien explaining how
vaccines protect us. Remember there is a lot of misinformation about vaccines
out there. So, please share this information with your loved ones, with your
friends and your networks, and be the source of scientific, evidence-based
information. Until next time then. Stay safe, stay healthy and stick with
science.