Today, municipal authorities are facing a backlash. A US-based academic site that published his article, SocArXiv, took it down last Friday, accusing him of “promoting unproven medical treatment amid a global pandemic.” The site accused city officials of bad science and unethical behavior — effectively, using citizens like rats in a giant lab experiment without their consent.
The decision blew up a storm on social media. Opposition politicians are calling for an investigation.
What makes the scandal remarkable is not just the scale of the Mexico City program – nearly 200,000 kits containing ivermectin were distributed – but who was advocating it. Unlike in the United States, where ivermectin has been promoted by conservative commentators (and star podcaster Joe Rogan), the drug has been championed in Mexico by leftist intellectuals in high government positions.
Mexico City’s government has boasted of confronting the coronavirus with science-based policies, including large-scale testing and vaccinations. Mayor Claudia Sheinbaum holds a doctorate in environmental engineering. Yet even as Mexico’s federal government warned against using ivermectin to treat the disease, desperate city leaders were drawn to a drug that dazzled politicians from Alaska to India .
The Mexico City program began in December 2020. Covid-19 cases were skyrocketing and hospitals were in lockdown. An alarmed city government provided medical kits to patients who tested positive for the coronavirus and had mild to moderate symptoms. Each contained four ivermectin tablets.
After distributing 83,000 kits, the government calculated the numbers. It reported a drop of at least 52% in hospital admissions among those who had received the kits, compared to others previously infected. “It’s great news to be able to validate our policy,” tweeted city official Jose Merino.
At first, the government study seemed destined to fade into oblivion, like many of the documents submitted to SocArXiv. “I wasn’t even aware of that,” said Philip N. Cohen, the University of Maryland sociologist who manages the online archive, which contains more than 8,000 research papers. “Until it explodes.”
SocArXiv, founded in 2016, provides a forum for social scientists to share their research before it is peer reviewed. These sites have become more popular as academics try to publish their latest findings – and get quick feedback from colleagues – in the rapidly changing era of coronavirus.
At the end of 2021, Cohen was surprised to see that the top paper that year had been the study “Ivermectin and the odds of hospitalization due to COVID-19” based on the Mexico City program. It had been downloaded over 10,000 times.
Then Cohen started hearing from academics — including Juan Pablo Pardo-Guerra, a sociologist at the University of California, San Diego, who wrote a widely shared Twitter thread attacking Mexico City’s work. “This article is comparable in its ethical dimensions to the infamous Tuskegee study,” he wrote. The Tuskegee Experiment was a 40-year study in which the United States Public Health Service observed the effects of syphilis in hundreds of black men without informing them of their diagnosis or treating the disease.
Cohen and his colleagues reviewed Mexico’s document and concluded that it had multiple problems.
The first was that the medical kits included not only ivermectin, but also paracetamol, aspirin and oximeters. It was unclear which of the items might have improved the patients’ health, Cohen said, and the study subjects were not randomly selected, like in a clinical trial. Additionally, the city government had not declared its conflict of interest, i.e., it would benefit if the study presented the program as a success. And the city was mass-distributing a drug that international authorities, including the World Health Organization, say should only be used to treat covid-19 in clinical trials.
What was most concerning to Cohen was that the 10,000 downloads were probably not the result of scientists questioning the merits of the program. “We believed the newspaper was being used to spread misinformation,” Cohen said.
Authorities in Mexico City denied that the program was an unethical experiment.
Health Secretary Oliva López Arellano said the decision to use ivermectin was made at “a different time” in the pandemic, before vaccines were widely available. Some other cities around the world were also offering the drug to citizens sick from the pandemic, she said. Although she acknowledged the controversy, “it was more in terms of whether it was helpful” in treating covid-19, she said, and not whether small doses could cause harm.
The real problem was not such limited doses, she said, but a trend in the United States and elsewhere of citizens poisoning themselves with large amounts of ivermectin, or even using a version intended for animals. “What we want to point out is that all the kits have always been distributed by medical professionals, with safe doses,” she said.
It is highly unusual for a government agency to distribute a drug that even the country’s drug regulatory body has not authorized to treat a disease. Mexico’s top health officials – including coronavirus czar Hugo López-Gatell – have consistently warned citizens not to use ivermectin for covid-19.
Merino, the lead author of the Mexico City study, accused Cohen of being “colonialist and authoritarian” in retracting the article. Merino, a political scientist who directs the city’s Digital Agency for Public Innovation, acknowledged that the ivermectin study was not a clinical trial, but rather an observational study, in which researchers analyze the effect of an intervention without controlling who is affected.
“It is very obvious that in the United States the mere mention of ivermectin triggers political and media delirium,” he wrote in a letter signed by most of the study’s co-authors.
Mexico City stopped distributing ivermectin in September and is now basing its covid-19 strategy on vaccines.
Sheinbaum, a protege of President Andrés Manuel López Obrador, is widely seen as one of the best candidates to succeed him when his term ends in 2024. From the start of the pandemic, his government has tried to distance itself from efforts to López Obrador to minimize coronavirus, urging greater use of masks and coronavirus testing,
Yet the densely populated city has been one of the hardest hit capitals in the world during the pandemic. According to government estimates, it has suffered more than 86,000 deaths from covid-19.