- Anthony Fauci, one of the top US experts on infectious disease, is the face of America's coronavirus response team.
- Comedy Central's "The Daily Show" host Trevor Noah asked Fauci whether people who are infected with COVID-19 and recover from the disease are immune to reinfection in an interview Thursday.
- Fauci responded that, while experts can't be 100% sure, he feels "really confident" that recovered coronavirus patients will have immunity.
- He added that he'd be "willing to bet anything that people who recover are really protected against re-infection."
- Visit Business Insider's homepage for more stories.
Dr. Anthony Fauci, one of the top US experts on infectious disease who guided the US through the AIDS, Zika, and Ebola epidemics, shared an optimistic message this week as he leads the country's response to the coronavirus outbreak.
During a recent interview with Comedy Central's "The Daily Show" host Trevor Noah, Dr. Fauci was asked whether people who are infected with COVID-19 and recover from the disease are immune to reinfection. Scientists are still working to answer this question, which could play a crucial role in decisions about whether to let people who have recovered out of lockdown.
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Fauci, who has often appeared at odds with the White House's more positive messaging around the pandemic, told Noah that, while experts can't be 100% sure yet, he feels "really confident" that recovered coronavirus patients will have immunity.
He added that he'd be "willing to bet anything that people who recover are really protected against re-infection."
Immunity to the coronavirus
While there are still many unknowns about the coronavirus, Noah's question to Fauci is among the most important lingering mysteries about the virus that has spread to at least 177 countries and infected more than 615,000 people.
One of the reasons the illness has spread so quickly is because it's a new virus our bodies have not encountered before — so we have no built-in immunity. The immune system has to develop antibodies — proteins that fight a specific antigen — before we become protected.
Generally, once your body has antibodies that can fight off a particular virus, you can't get sick from it again. That's why someone who had chickenpox or got the vaccine won't get the disease twice.
Fauci told Noah that "if this virus acts like every other virus that we know, once you get infected, get better, clear the virus, then you'll have immunity that will protect you against re-infection."
So far, the number of recovered coronavirus patients — 135,700 — is about one-fifth the number of infected.
Further research is needed to confirm Fauci's statement
Fauci told Noah that more research is needed to confirm whether recovered coronavirus patients have been protected.
"We don't know that for 100% certain because we haven't done the study," said Fauci, who's worked in the public health sector for more than half his life and has been the director of the National Institute of Allergy and Infectious Diseases (NIAID) since 1984, advising six presidents.
In a March study (which has yet to be peer-reviewed), a group of scientists infected rhesus macaques with the novel coronavirus, let them recover, then tried to reinfect them. The first infection gave some of the monkeys a mild illness, resulting in moderate pneumonia and weight loss, but the second did not seem to affect any of them.
A month prior however, a report from Japan revealed that a tour guide had recovered from the coronavirus, then tested positive for it again three weeks later. Doctors aren't sure if she was reinfected or had not fully recovered from the first infection.
A study from Chinese researchers on healthcare workers who recovered from the SARS coronavirus in 2002 found that the number of SARS antibodies peaked in patients' bloodstreams in 2004, and declined afterward until the study ended in 2015. (The study was released in the preprint server MedRx last month, but also hasn't been peer-reviewed yet.)
These "antibodies have neutralization activities and provide protection against infections," the researchers wrote. They're an indicator that these recovered patients had some immunity to SARS, they added, but it's unclear if those antibodies provide "complete protection" from reinfection years later.
Because the new coronavirus shares 79.5% of its genetic code with SARS, it's possible that the antibodies for the new coronavirus might behave similarly.
William Campbell-Corbis via Getty Images
If further studies reveal that Fauci is correct, and recovered coronavirus patients are immune to reinfection for at least some amount of time, that could prove pivotal in the US government's efforts to relax the lockdowns and social distancing measures that are wreaking havoc on the economy.
Currently there are 23 states and eight metro areas under various stay-at-home orders, which means approximately 169 million people — nearly 52% of the US population — are only going out for essential services like buying food and medicine.
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