In the first few months of 2020, a new and deadly disease killed and quarantined thousands, panicked millions, and made international news. The new virus, dubbed COVID-19 or 2019-nCoV, is a type of coronavirus; two of the best known and most deadly are SARS (severe acute respiratory syndrome, first identified in 2003) and MERS (Middle East respiratory syndrome, in 2012). The symptoms of 2019-nCoV are typical of influenza and include a cough, sometimes with a fever, shortness of breath, nausea, vomiting, and/or diarrhea. About 80 percent of infected patients recover within a week or two, like with a bad cold, and 20 percent contract severe infections such as pneumonia, sometimes leading to death.

The 2019-nCoV virus is spreading faster than either MERS or SARS, but it’s much less deadly than either. The death rate for 2019-nCoV is 2 percent, compared to 10 percent for SARS and 35 percent for MERS. There’s no vaccine, and because it’s not bacterial, antibiotics won’t help. The first case was reported in late December 2019 in Wuhan, China. About a month later, a U.S. public health emergency was announced.

In addition to sickened patients, quarantines, and outbreaks, epidemiologists were dealing with an outbreak of rumor and misinformation about the virus. It didn’t help that Chinese officials were slow to share information and admit the scope of the outbreak, due in part to the government’s longstanding policies of restricting news reporting.

Xenophobia and contamination fears are common in disease rumors. Many reports in news media and social media focus on the “other,” the dirty aberrant outsiders who “created” or spread the menace.

In the case of 2019-nCoV, rumors suggested that seemingly bizarre eating habits of the Chinese were to blame, specifically consuming bat meat. More recent investigation suggests that an endangered animal, the pangolin, might be responsible, but epidemiologists haven’t definitively found the origin.

Then there are conspiracies, prominent among them about the disease’s origin. Several are circulating, claiming, for example, that 2019-nCoV is a bioweapon either intentionally deployed or escaped/stolen from a secure laboratory. In late February, Arkansas senator Tom Cotton gave credence to it in an interview with Fox News, suggesting that 2019-nCoV might have been “a deliberate release” from a top-secret bioweapons laboratory in Wuhan. (He later admitted that he had no evidence and that it was merely one of many theories he thought he’d share.)

Many of the 2019-nCoV rumors and myths concerned ways to prevent or cure the virus. They include avoiding spicy foods, eating garlic, and drinking a “miracle mineral solution,” 28 percent sodium chlorite mixed in distilled water, being sold online for about $30 for a four-ounce bottle. Skeptics have debunked this substance for many years, noting that the solution is not only ineffective but potentially harmful.

Folk remedies such as these are appealing because they are something that victims (and potential victims) can do—some tangible way they can take action and assume control over their own health and lives. When people are frightened by diseases, they cling to any information and often distrust official information. These fears are amplified by the fact that the virus is of course invisible to the eye and fueled by ambiguity and uncertainty about who’s a threat, because carriers may be asymptomatic.

Even debunked psychic Sylvia Browne got in on the act, albeit posthumously. In early March, information circulated online about a prediction she made in her 2008 book End of Days:

In around 2020 a severe pneumonia-like illness will spread throughout the globe, attacking the lungs and the bronchial tubes and resisting all known treatments. Almost more baffling than the illness itself will be the fact that it will suddenly vanish as quickly as it arrived, attack again ten years later, and then disappear completely.

This led to many on social media assuming that Browne had accurately predicted the Covid-19 outbreak. I wrote an online piece (at https://tinyurl.com/wpa39hu) analyzing her prediction—which later was quoted in a Newsweek article—noting for example that “around 2020” covers about seven years; the virus is not “a severe pneumonia-like illness” nor does it “resist all known treatments”; and for that matter, it hasn’t “suddenly vanished as quickly as it arrived” (and we can’t know for another decade whether it returns). I concluded that we have a two-sentence prediction written in 2008 by a convicted felon with a long track record of failures. Half of the prediction (the second sentence) has demonstrably not happened. The other half of the prophecy describes an infectious respiratory illness that does not resemble Covid-19 in its particulars that would happen sometime within a few years of 2020.

Hoaxes, misinformation, and rumors can cause real harm during public health emergencies. When people are sick or desperately afraid of a scary disease, any information will be taken seriously by some people. False rumors can not only kill but hinder public health efforts. The best advice is to keep threats in perspective, recognize the social functions of rumors, and heed advice from medical professionals instead of your friend’s friend on Twitter.