Antibodies are a type of protein molecule
that your immune system produces
as it fights infection.
Antibodies circulate in the blood
and other body fluids
and they act as sentinels to help keep us healthy.
And the interesting thing about antibodies
is that the they're capable of attaching to the specific germs
that cause antibodies to be made in the first place.
So, people who are infected with the novel coronavirus
make antibodies that specifically recognize that virus
and not other types of viruses.
By analogy, think of a lock and key.
The key is made to open a specific lock
and not another lock.
So we’re still learning about the novel coronavirus,
but we do know that antibodies against it become detectable
several days after symptoms begin.
These antibodies are like fingerprints
that tell us the virus has caused an infection
and that our immune system has responded.
Now the strength of the antibody response
to the virus really depends on several things,
like the person's age, their nutritional status,
how severe their COVID-19 illness was,
and whether or not they have conditions
or are taking medications that
could affect how well their immune system responds.
The other important thing to remember is that
antibodies usually remain in the blood for some period of time
and they act like guards that can quickly
restart the immune system
or activate the immune system
when someone has been exposed
a second time to that same infection
that caused them to be made.
Now with some infections,
antibodies not only recognize when a past infection returns
but they also keep us from getting the same illness again,
like think of the measles.
Other times though, the protection that antibodies give us
lasts only a short time,
as we see with seasonal flu.
And right now, we don’t know
how long antibodies to the novel coronavirus last
or if they even give us short- or long-term immunity.
And that's really important for us to know
because doctors want to be able to use
the results of these antibody tests
to determine if someone is immune or not.
But we just don't know the answer to that question.
And until we do,
these antibody tests to novel coronavirus
really only tell us that you have had an infection.
