EAT GARLIC AND YOU WON’T GET THE VIRUS. Gargle with bleach. Or just drink hot water with lots of lemon juice. Misinformation about COVID-19 has been spreading as widely as the virus itself, as the U.N. Secretary-General noted in March, making the pandemic harder to quell and causing real harm in its wake.

These kinds of online falsehoods hurt everyone. But they do far more damage among already vulnerable social and economic groups, says Kasisomayajula “Vish” Viswanath, a professor of health communication at the Harvard T.H. Chan School of Public Health. Viswanath has studied past epidemics and looked at how misinformation spreads. He notes that social factors—income, ethnicity—can especially affect how people receive and act on information about health threats.

Q: You’ve written about communication inequality. What is that?
A: Different socioeconomic groups, racial and ethnic groups, rural dwellers—each of these can face tremendous inequalities in the type of information they receive and media from which they receive it. We have robust evidence that those differences affect how people pick up health messages, not only during a public health emergency like this pandemic but also when we try to manage noncommunicable diseases.

For example, I was involved in research around H1N1, a dangerous strain of flu that saw a pandemic in 2009. People with higher incomes and education levels had types of media exposure that led to them being more knowledgeable about the H1N1 virus. These groups also had a greater trust in public officials and in public information sources, which made them heed public health messages and be more likely to get the vaccine and to adopt practices like social distancing and hand washing. For them, the current system works. For others, not so much. We can see similar factors at play with cancer-related health information; while some groups are getting these messages, lower socioeconomic groups are just less likely to.

Q: How are social inequalities responsible for that gap?
A: Low literacy, innumeracy, speaking a language other than English—these can all be obvious barriers to hearing a public health message. Having less prior knowledge of a subject—which goes hand in hand with less education and a lack of exposure to these topics—also makes it more difficult to process subsequent information about it. Perhaps we take for granted the concepts that play into even simple health messages. Some groups have a deep-seated distrust of authority based on how they have been treated or how their group has been treated. There are also consumption habits. Underserved communities don’t generally read The New York Times or even the local paper. They get their news mainly on TV or social media, and research shows that getting information mainly from social media leads to people having less accurate information about the virus.

We also know that many poor households lack consistent access to broadband services. They lose cell phone connection every few months because they can’t pay the bills. But beyond that, they may also have other, tremendous stressors in their lives. They face evictions; they move from place to place or are in shelters. A scarcity of time and resources can make it difficult to focus on health. They are trying to cope with this flood of disinformation coming at them while at the same time worrying about rent coming due or getting child care now that the day care is closed.

Q: What can public health communicators do to counter this?
A: We need to reach all populations, especially those at a disadvantage because those people often face greater risks. Existing relationships can be key, so my colleagues and I have been focusing on what we call “participatory interventions.” We work with trusted, community-based organizations—a domestic violence center, food center or community health clinic—to disseminate information. The organization helps shape the format it feels is appropriate for its audience. You want to reach people where they are, so they don’t have to come to you.

Q: How do you hone a message so that it sticks?
A: Particularly in times of public health emergencies, it is best to focus on the science that people need to know—the core message that is important for day-to-day needs. On COVID-19, there is so much information out there. But sending out daily, weekly or even monthly developments on the research — these are interesting, but rapidly changing science and health information has the potential to sow confusion. It makes people question their trust in authorities, and this is true for any group.

Q: What about people on the front lines—researchers, clinicians, politicians—sharing their takes on the best way forward? Is this helping or hurting?
A: When they’re sharing information about what to do in areas where we have broad consensus—that is helpful. But offering differing opinions often is not. For instance, take the current controversy on using anti-malarial drugs to treat COVID-19 patients. Public disagreement or discordance on guidelines can make it very difficult for lay people to assess information accuracy. If you are one politician disagreeing with another, it makes for good TV, but it doesn’t help with our objective in health care, which is to get the public on board with doing things we know are beneficial. The debates tend to reinforce cynicism and skepticism. What am I supposed to think? What am I supposed to do to protect my life?

Q: What responsibilities do each of us have when it comes to sharing COVID-19 information responsibly?
A: We have itchy fingers, but it’s important to have a critical mindset about what you’re about to share. Is it from a reliable source, and why do you think so? You don’t have to forward every message you get. I tell people to be skeptical, not cynical. I also encourage people to use social media to show generosity and kindness, messages like “What do you need? How are you doing?” If you share information, you have an obligation for it to be evidence-based. But you don’t have to run a randomized controlled trial to be kind on social media.

If you have questions about COVID-19, my team has set up a web dashboard with facts in English, Spanish and Portuguese. We have been putting out simple, foundational information such as what COVID-19 is and how it is transmitted. We hope that helps cut through the clutter. Beyond that, we tell people to do their own research, and to go to a few reliable sources, including the Centers for Disease Control and Prevention and the World Health Organization.