Chloroquine isn't a miracle cure. A tiny amount can poison you.

Confirmation bias is the central conundrum in "fake news." People with a lot of followers can say just about anything, and if they hit on a general bias in people's desires, they're believed. The one true desire unifying us all right now is for this coronavirus madness to end.

So when a lawyer and a blockchain investor recently mused on Twitter that the anti-malaria drug chloroquine was a cure for COVID-19, the disease caused by the novel coronavirus, they hit the jackpot in confirmation bias: They made the right people believe that a magic-bullet drug will rescue us. Elon Musk tweeted about it. The lawyer was invited on Fox News to talk about it. Then our Fox News-watching president amplified it in a news briefing and on Twitter, reaching millions and all major news outlets.

And now, as public health experts try to keep all 330 million Americans focused on social distancing, hand-washing and local health authorities' region-specific instructions (so important as the infection curves unfold state by state), they also have to mitigate the damage done by false hope in a magic-bullet medication.

Already, Nigeria has multiple reports of poisonings of people self-medicating with chloroquine against COVID-19. One man died Monday in Arizona after he and his wife ingested a chemical made of chloroquine phosphate — used to kill parasites on their pet fish — thinking they were protecting themselves from COVID-19. His wife survived after vomiting up the chemical.

Hope in this 75-year-old drug started after recent French and Chinese studies were released, claiming that chloroquine could stop the coronavirus from becoming deadly. The director of the National Institute of Allergy and Infectious Diseases, Anthony S. Fauci, warned that these studies were small, ad hoc and anecdotal, not randomized and double blind (necessary to avoid biased results) — which means researchers have no reliable evidence that the treatment works.

We need to listen to Fauci, wait for the evidence and be prepared to accept the results.

I wrote about the false promise of chloroquine in a book about malaria and World War II. I retrieved from the National Archives the toxicity trials run on hundreds of prisoners and enlisted servicemen. As war raged overseas, federal scientists in the Stateville prison near Chicago dosed inmate "volunteers" with 0.3 grams of chloroquine a day — half of what the French used in their COVID-19 study.

In a parallel project in Klamath Falls, Ore., U.S. Marines sent home from Guadalcanal with relapsing malaria were given even higher doses of an analogue of chloroquine, called sontochin. Navy doctor and malaria expert Lowell Coggeshall gave the men 5 grams a week — 2 grams less than the Chinese used in their COVID-19 studies. Coggeshall had to stop the study when the Marines developed double vision, irritability, anxiety and itchy hives so intense that they had to be given a sedative. He gave up on the chloroquine line of drugs as a possible cure for relapsing malaria.

This 1940s hunt for a cure, nicknamed the Malaria Project, was declared the No. 1 medical priority of the war because the disease had taken down hundreds of thousands of troops, especially in the Pacific theater. When the war ended, the project announced chloroquine as its magic-bullet cure. Many flaws in the drug were overlooked. Trials on large populations in South America were fudged to allow federal authorities to write unequivocal news releases about the success of this massive program (which was run by the same secret White House office as the Manhattan Project: the Office of Scientific Research and Development).

In the 1950s and 1960s, over the strong objections of public health experts at the Rockefeller Foundation (that era's equivalent of today's Gates Foundation), federal authorities pressed chloroquine into duty in a worldwide malaria eradication campaign. Millions of people in poor countries were given low doses of the drug to sanitize their blood of the parasites that cause malaria. But these masses refused to conform. Too often, they stopped taking the drug before the required time because of the side effects, which even in low doses included headaches, itchy skin and ringing in the ears — plus serious heart-related complications when taken with other medicines. Malarial parasites quickly developed resistance, and the drug was taken out of circulation. The decades-long effort failed. It was a classic trick played on a world too prone to magic-bullet thinking.

In today's COVID-19 world, we need to listen when public health officials tell us that this drug has downsides. The recent French and Chinese studies on chloroquine and COVID-19 may show no notable side effects in their small sample sizes — patients hospitalized with pneumonia in China and in various stages of the disease in France. But we know that the large doses used in their studies can be unsafe. So even if chloroquine proves useful in stopping the virus in severe COVID-19 cases, it could prove more dangerous than the virus itself in many people with milder coronavirus infections.

That's why real research is needed, and that takes time. New York Gov. Andrew Cuomo said he obtained 750,000 doses of chloroquine and 70,000 doses of hydroxychloroquine to begin trials immediately. Other trials are ongoing elsewhere. If the studies pan out, strict supervision of the drug's administration may be the protocol, not over-the-counter sales to treat the masses. Experts know too well what is likely to happen: Chloroquine will fail to magically stop the coronavirus madness. The good news, however, may be that it ends up saving some lives.

But for the sake of honesty about what is really happening in the search for a treatment, we need to hear the experts and amplify their voices so the rest of us may be protected from the charlatans.

We all want to be saved from this nightmare, but not falsely. No magic, please. No tricks that tap our deepest desires. Just solid, reliable information.

Karen M. Masterson, author of "The Malaria Project," is a professor of science journalism at Stony Brook University. She wrote this article for the Washington Post.