Medical Examiner

How Public Health Experts Feel About Being Wrong

That they change their advice is actually why we should trust them.

Fauci wearing a red mask
Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, adjusts a Washington Nationals protective mask. Pool/Getty Images

“There’s no reason to be walking around with a mask,” Anthony Fauci told 60 Minutes back in March. Since, then, of course, that recommendation has turned upside down: Everyone should be walking around in a mask like the future of America depends on it.

The no-mask directive is part of a list White House aides are circulating to media outlets, showing examples of things Fauci said early in the pandemic that now seem disturbingly out of touch. Other alleged missteps include suggesting asymptomatic carriers aren’t likely to be a huge problem and that Americans don’t need to change their routines.

We are learning new things about a novel virus by the day, so it’s disingenuous to pull these statements out of their larger contexts and unmoor them from their timestamps. But also: It is jarring to be living through so many shifts in advice. I wanted to know how public health experts thought, and felt, about one of the biggest and clearest mistakes in public health advice of this pandemic: that now-flipped directive about masks.

“It would be really concerning to me if we were dealing with a novel pathogen and the guidance never evolved,” says Saskia Popescu, an infectious disease epidemiologist. When I spoke to her for a story about masks earlier in the pandemic, she, like many experts, emphasized that, among the public, masks were really most useful for people who were clearly sick. She was leaning on the heuristic of what we do—or in the case of masks, don’t do—in flu season (here in the States at least). Unlike the flu, the coronavirus, we now know, can spread via hosts without clear symptoms, and via not just large droplets expelled from coughs, but via smaller particles breathed into the air. A virus that can travel from someone’s mouth without them really knowing—that’s a situation in which masks are more clearly useful. As we learned more about the new virus, it made sense to update the advice. For scientists, updates that follow new information are “a really good thing,” as Popescu notes. Flips in advice are a sign that we know more, and that experts and institutions are responding to new information. In a fast-moving situation, advice that has been updated can in fact be more trustworthy.

Health advice is often subject to change, or can even vary depending on which expert you ask, as anyone who has waded through nutrition advice or inspected the claims on wellness products knows. Experts are well-informed humans who are ultimately making judgment calls. “If you think in health care that everyone you speak to is assured of what they’re saying with 100 percent certainty, you’re going to be disappointed,” Aaron Carroll, a professor of pediatrics at Indiana University School of Medicine, told me. Back at the beginning of April, he was featured on Slate’s podcast What Next making a case against masks to host Mary Harris. “We’re making our best guesses,” Carroll says now. Even in the face of new information, it can take time and discussion to update those guesses, as an incredibly detailed account of the mechanics behind the flip by Megan Molteni and Adam Rogers in Wired shows. Strikingly, there was significant lag time between reports of people without symptoms spreading infection, warnings from experts in airborne transmission, and changes in directives on masking from the Centers for Disease Control and Prevention and the World Health Organization, which came in April and June, respectively. Even now, as it’s clearer that we should wear them, the exact amount of protection masks offer us from one another is unclear. “There still aren’t randomized, controlled trials of mask wearing against COVID-19—how would you even do that?,” write Molteni and Rogers. Untangling the nuances of masks, and other aspects of safety, will take more experiments and more experiences with the coronavirus.

How do we navigate health advice in the meantime? If you’re sharing a best guess—or betting your safety on someone else’s—it’s important to be able to share and understand the full thinking behind the guess. “Be truthful, be accurate, but be complete,” said Robert Amler, a former CDC chief medical officer, now at New York Medical College, on how he thinks about advice. “The No. 1 rule I have learned, honestly, is work with journalists,” he says (indeed, I met him through a publicist). Being purposeful about media can help experts get their full thinking across. Since March, in addition to flipping the bottom line on masks, Carroll says he’s stopped going on cable news, where he has very little time to respond to questions. “If people say ‘Should we wear masks?’ I need Mary’s 25-minute podcast to answer the question.”

Which brings me to something that Popescu, Amler, and Carroll each maintained: Their thinking on masks as a concept has not shifted as dramatically as it might seem. Reporter Maggie Koerth makes this point in a FiveThirtyEight piece: The science of masks themselves hasn’t changed so much as the way we’re interpreting it as we get further along in dealing with the virus they are meant to control. What the public sees as a flip is a smaller factual update to experts who need a good 25 minutes to lay out all the things they know and don’t know about the subject of whether you should wear a mask. Going back and reading my and my colleague’s early interviews with these experts, I was struck at how much, in fact, wasn’t wrong. Cloth and surgical masks still protect other people, not so much the wearer. The most important thing is still social distancing in the first place. In the face of a shortage, it’s healthiest for all of us if the available supplies go to medical workers. On the last point, one thing Carroll does admit could have been clearer: When he used the word mask, he meant surgical and N95 masks, which needed to be reserved for health care workers. When other people said mask, they sometimes referred to homemade fabric masks, which always stood to offer a little (if also hotly debated) amount of security, at no expense to health care workers. “We just said ‘mask,’ when it meant all of those things,” he says.

So yes, that was a mistake—though at the time it wasn’t as evident how important filling in the nuance around the word masks would turn out to be. Even honest failures in communicating nuance, or good-faith guesses that turn out to be wrong, can erode public trust. “It’s heartbreaking, and it’s hard,” says Popescu. “I always try to say, ‘This is likely to be the case,’ or ‘This is what the data is leaning towards,’ ” she says. Translating data, with all its caveats and error bars, into something that people can do is an art.

Update, July 16, 2020: This post has been updated to included co-author Megan Molteni when citing the Wired article about masks.