• Covid-19
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COVID-19 Reinfection and You

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Medical experts in Pitt’s COVID-19 Medical Response Office (CMRO) want to dispel a common misconception about COVID-19. You can, in fact, get the virus twice. And even if your symptoms are mild, you’re still able to spread the virus to others.

Pittwire recently spoke with John V. Williams, director of the CMRO, and colleagues including pediatric infectious disease fellow Megan Freeman about reinfection, ahead of the Thanksgiving break and as flu season ramps up.

So, is it possible to get reinfected with the same COVID-19 variant?

It is possible! Based on historical studies of other respiratory viruses that behave similar to this coronavirus, we know that people can get reinfected, even with the same strain. And we know that there’s at least one major mutation for COVID-19. So, just because you got it once doesn’t mean you can’t get it again.

If you do get reinfected with the same variant, it’s likely to be less severe the second time around because of your body’s immune response having developed antibodies to the virus. But the risk to you in this case is secondary. The bigger concern is someone becoming reinfected with the same variant, not getting sick themselves, but still being contagious to others. You can get infected twice and be asymptomatic the second time around, and still carry it and transmit it to other more vulnerable people around you. It’s a huge public health issue.

I (Williams) think reinfection is going to be more common than we think, and this is why in the CMRO we’ve really been pushing the Centers for Disease Control and Prevention line that there are no superheroes.

How many variants of SARS-CoV-2 are out there now? Aren’t there hundreds of variants?

There are two major variants with a single amino acid mutation in one protein that’s of unclear biologic significance. People think that one of the mutations might have made it spread better but there’s not great evidence for that.

In other words, there is some infection that we don’t think makes sickness any more severe, but that could actually facilitate reinfection the way flu does. We know mutation is happening to some extent that may add to the risk of reinfection.

Do coronaviruses mutate in a similar way to the flu, where if you get one flu vaccine you’re probably protected against a second strain?

Yes and no. Coronaviruses do mutate, though not quite as much as flu. But part of the reason why people get infected with flu every year is because there is a little bit of mutation. That’s why to prevent severe disease, you should get a new flu shot every year. Respiratory viruses like flu and SARS-CoV-2, the virus that causes COVID-19, infect mucosal surfaces. They don’t invade the body the same way that meningitis, measles or rubella viruses do.

Our immunity is really good at sterilizing things that go through the blood, things like meningitis, measles, rubella. But for viruses that don’t go deeper than a mucosal level, our immune system is just not as equipped to prevent those. That’s where vaccines come into play. They reduce the severity of severe disease. People have been working for decades to find an effective vaccine to completely prevent mucosal surface infections like influenza. We haven’t yet found a way to do that.

Also, infection prevention is different from reducing disease severity. Vaccines can help with both. So, similar to the way the flu vaccine helps reduce the severity of future infections, a COVID-19 vaccine will be incredibly effective at dramatically reducing severe disease.

If it’s true that reinfection is possible but unlikely, couldn’t I just get COVID-19 once, hunker down with my household and wait it out so we can all stop worrying so much about it?

No, and here’s why: One, this virus does not affect everyone equally. Two, there’s no way to know how anybody’s immune system will respond or what complications may arise. Three, why risk spreading it to others?

It’s not typically a matter of life and death when you’re around your own peer group. College students are less likely to suffer serious illness or complications from COVID-19. But it isn’t impossible for young adults to suffer serious complications, and we are still learning about the long-term effects. And with everyone returning home for Thanksgiving, we’re expanding our circles beyond just our peer groups now. We’re all going to be around new close contacts, some of whom will be more vulnerable.

So, hunkering down and waiting it out may reduce your personal risk of getting seriously sick if you’re a young, healthy college student. But that same behavior could mean a hospital stay for family members—unfortunately, there’s just no way to know how bad it will be. And having antibodies yourself does not make you immune to spreading the virus. We’re in a pandemic. We’re dealing with collective risk. That’s why the logic of ‘getting it once to get it over with’ doesn’t work here.