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Whether you've already gotten one or you're waiting to get one,
the COVID-19 vaccines are on everybody's mind.
So we thought it would be a good idea to talk about just how vaccines work, and
how the new viral variants are complicating the picture.
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The first cases of COVID-19 in the US were diagnosed in January 2020.
And the first COVID-19 vaccines were made available to the public in December 2020.
>> Usually it takes three to five years or five to ten years to get to a vaccine
being available so that it can be widely distributed.
To begin and complete the vaccination process in such a short period of time is
definitely a triumph of modern science, I mean, it's absolutely amazing.
>> The first COVID-19 vaccines deployed in the US were produced by Moderna and
Pfizer Biontech, followed shortly by the Johnson and Johnson vaccine.
And there are more on the way.
They all work pretty much the same way, by preparing the human body to defend itself
against SARS-CoV-2, the virus that causes COVID-19 before it's ever infected.
>> So we come in contact with a substance, a virus, a bacteria,
a pathogen, a piece of food.
And our body sees that, and when it's a new substance,
it defines what that substance is and then it codes an action for it.
>> That action is your body's immune response.
If the new substance is a pathogen, your immune response creates what are called
antibodies, which fight off infection.
The COVID-19 vaccines prompt your immune system to create
the specific antibodies that protect against SARS-CoV-2.
>> That way, as that viral antigen comes to your doorstep,
the antibody comes out to greet it and says, no, not so fast.
[LAUGH] You're not allowed here, you're not wanted, and clears it from the body.
>> Part of why vaccines are so good at combating disease is that they
don't just protect the person who gets the shot.
They also protect those around you, but only if enough people get it.
That's because of a phenomenon called herd immunity.
>> Herd immunity basically refers to the proportion of a population
that needs to be vaccinated to prevent ongoing transmission in that community.
>> If we can reach a certain level of immunity in the population, and
we think that that level's around 60 to 70%, then transmission's gonna slow.
>> Vaccinating more people more quickly reduces the risk for all of us.
This is especially important,
because we know that like all viruses SARS-CoV-2 mutates as it spreads.
Variants of the original virus have already led to an uptick in
cases in the United States.
>> One of the things that we never thought we would have to worry about with vaccines
is resistance.
But with the variants we have seen that the more replication you have,
the more opportunities you have for that virus to mutate, to evolve.
>> Because the pandemic has caused so many people around the world to become
infected, the virus has been able to evolve quickly.
With each new infection providing SARS-CoV-2 an opportunity to become
stronger and smarter, which means more infectious.
>> The challenge with these is that if they change enough, and
an individual's immune response to the earlier forms of the virus doesn't work
anymore, then those people are at risk for reinfection.
>> So if SARS-CoV-2 is able to mutate fast enough,
it might change so much that the vaccines are no longer as effective as they were
on earlier variants of the virus.
But the medical community is no stranger to viruses that mutate,
take the influenza virus.
The reason you have to get a new flu shot every year is because of how fast
the influenza virus mutates.
>> With SARS-CoV-2 it's a different story.
It mutates more slowly than something like, say, the influenza virus.
And that's good news, in a way, we're in a position where we can use our
modern methods to track the evolution of the virus and then to tweak the vaccine.
Or at least to show that the vaccine covers, say, some of the new mutants.
>> So does that mean we might eventually need to get booster shots of the COVID-19
vaccine?
>> More likely than not we will need boosters.
I doubt it's gonna be annually, but it may be every couple of years, and
that will need to be based on the best available molecular epidemiologic data.
>> As more and more people get vaccinated, the population will get closer to
the critical number that allows us to achieve herd immunity.
But until we reach that goal, it's important to keep wearing masks and
socially distancing.
If we don't, the more infectious variants might cause another spike in cases.
Even so, these new vaccines have given us a glimmer of hope. After a long year of
living with the pandemic,
we have a chance to return to some sense of normalcy, especially as the vaccines
become available to more and more of the world with each passing week.
>> I think that the end is in sight.
I'm not saying that COVID is gonna go away completely,
we just don't have information enough for that.
But I do have evidence to say that these vaccines can transform our lives.
Please get vaccinated, if you're eligible, once you get all the facts.
I encourage it, I think it's a really good step, and
then take advantage of it in a safe way.
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