How and Why Some People Can Get COVID-19 Twice, According to Dr. Fauci

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With positivity rates skyrocketing over the last month, data from the Centers for Disease Control and Prevention confirms that 65 million and counting Americans have been diagnosed with a confirmed case of COVID-19. That's nearly 1 in every 5 of us.

But with this recent influx of cases and new variants (delta, omicron) popping up at a more rapid clip, you or someone you know may actually be counted in that number twice … or three times. That's right, it is possible to get reinfected with coronavirus, which makes herd immunity even more complicated.

Related: Will Everyone Eventually Get COVID-19? Here's What Experts Say

With all of this in mind and with new cases still topping 850,000 per day for the last week, on Friday, January 14, Katie Couric hopped on a virtual chat with Anthony Fauci, M.D., the director of the National Institute of Allergy and Infectious Diseases, to talk through all of our infection FAQs.

The CDC defines "reinfection" as getting sick once, recovering from that illness, then later getting infected with the illness again. Fauci told Couric that this phenomenon is especially common among those who had fallen ill due to an earlier variant.

So why can't we kick this? And why don't the antibodies help protect us from a second or third round in the boxing match against COVID-19?

"This is a highly transmissible virus," Fauci said. "If you get infected in your upper airway and it goes to the lungs and goes throughout the body, you can get very, very seriously ill. But blocking the virus at the upper airway … you really need the immune system concentrated at the upper airway, which is not easy to do when you have a vaccine that is systemically given to you."

This is the exact reason why the common cold coronaviruses that circulate each year during the winter months have—and continue to—infect all of us time and time again, Fauci explained.

"But they are benign enough that you may get some sniffles or a sore throat and it goes away in a day or two. The immunity isn't profound … that's what we believe we're seeing with the pandemic," he added.

This is especially true regarding omicron, currently the dominant strain in the U.S., which has 36 mutations to its spike protein. Emerging research suggests that omicron multiplies remarkably rapidly in the body, possibly 70 times faster in the lungs, compared to the delta variant, for instance.

"Omicron is reinfecting people who were infected with delta and infected with beta. There's absolute data on that; if you are prior infected with another variant, omicron can much more readily infect you than the actual original variant that infected you," Fauci explained. (This is one of many reasons why health experts are now recommending that we retire cloth masks and step up to more protective KN95, N95 and KF94 masks.)

This doesn't necessarily mean that we'll all need another booster shot of the current vaccines. The scientific jury is still out about "what the durability of the third booster shot of an mRNA [Pfizer and Moderna] and the second shot of a J&J [Johnson & Johnson] are," Fauci said.

But if you haven't yet been boosted, it's still extremely wise to step up.

"Without scaring anybody, there is a possibility that there will be another variant and we've got to be prepared for it," Fauci said. Getting a booster shot for additional protection against future mutations is prudent.

Looking ahead, since so many people are still unvaccinated across the globe and positivity rates are still very high, Fauci explained that scientists are working tirelessly to create a "universal coronavirus or a pan-coronavirus vaccine or at least a pan-SARS coronavirus vaccine which means you can get all of the variants to be covered. You may not prevent infection from another variant, but you certainly will prevent severe disease from another variant."

Related: What to Do When You Think You Might Have COVID-19, but Can't Get a Test

We can't predict how long this development might take since this is a totally novel scientific discovery, Fauci added. But as far as herd immunity goes, it's likely we will eventually get to a similar place with COVID-19 as we are now with measles or polio, when "95% of the population is vaccinated so you've essentially eliminated it from society—not from the world but from society," he said. The mission with COVID-19 right now is to essentially turn down the firehose that's spraying with such force. We "might want enough herd immunity so that you get infected maybe, but you don't get sick," Fauci explained, as a great goal for now.

Up Next: What Is "Flurona"? COVID-19 and Flu Coinfections, Explained

The situation surrounding COVID-19 continues to change quickly; it's possible that information or data has changed since publication. While EatingWell is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations by using the CDC, WHO and their local public health department as resources.