Dr Carlos Chaccour ran into difficulty when he and his colleagues began recruiting patients in Peru for their study to determine the effect of a daily dose of the anti-parasitic drug ivermectin on people infected with Covid-19.
“We would call the patient and say, ‘You have just been diagnosed with Covid and you’re eligible for this study. Are you taking ivermectin?’” he says.
“And they would respond, ‘Of course’.”
The former health minister of Peru and leader of the study, Patricia García, told Nature: “Of about 10 people who come [to the hospital], I’d say eight have taken ivermectin and cannot participate in the study.”
Ivermectin has never been proven as an effective Covid treatment, and studies that said it was have been either poorly conducted, too small for their findings to be applied more widely or outright faked. Yet the drug’s popularity has soared.
One of the first fraudulent ivermectin studies was revealed just a few months into the pandemic, before it was even being widely used or promoted to treat the virus. That study found ivermectin was leading to improved and reduced mortality in hospitalised Covid-19 patients around the world. The paper was eventually retracted by the medical journal that published it after the data was found to have been falsified and the patients nonexistent.
But the damage had been done. Before the retraction, the Peruvian government included ivermectin in its national Covid-19 therapeutic guidelines, their advice partly informed by the ivermectin paper.
Other studies found ivermectin has no significant impact on Covid-19 patients’ viral load, and that further, larger studies are needed to properly assess any impact of ivermectin on Covid-19. Despite all this, the drug has taken off beyond Peru and is now being used all around the world, promoted by politicians, celebrities and even some doctors and scientists as a credible treatment for Covid-19.
Chaccour, who has been researching ivermectin for its ability to control tropical diseases for more than 15 years, says the hope and use of ivermectin is almost understandable when people are dying in waiting rooms and there is a lack of supply of Covid-19 vaccines.
Countries with widely available vaccines, such as the UK, US and Australia, have also been affected by the ivermectin hype, with people trying to obtain the drug and even resorting to taking formulations used to treat parasites in animals. General practitioners, in some cases, are gladly prescribing it. Influential politicians and controversial researchers frequently tweet studies purporting to support its use.
But more of those studies are proving problematic.
In July, Guardian Australia revealed results from a randomised control trial from Egypt had been retracted after serious ethical concerns were raised, along with questions around the data.
In September, Buzzfeed News reported that an influential study from Argentina claiming ivermectin prevented Covid-19 100% of the time contained suspect data and was based on flawed methodology.
Interrogating the research
In research, a control group is the group of study participants who do not receive the intervention – in this case ivermectin – and is an essential part of a reliable study. If most people are taking the drug you want to examine already you cannot do a proper clinical trial.
The control group and the experiment group should be similar in all other ways, such as gender split, age ranges, severity of Covid, and overall health, to increase the likelihood that any effect seen in the experiment group is a result of the intervention.
These studies are known as randomised control trials (RCTs) and the strongest of them are also “double blind” – neither the researchers nor the participants know which patients are receiving the intervention or the placebo treatment, which is usually a sugar pill or, in vaccine trials, a saline solution.
Because of the strength of RCTs, they are critical in the fight against Covid-19. The more participants enrolled in an RCT, the stronger the findings, and the more likely the findings will be “replicated” in future studies and when the intervention is given to the broader population. Governments and drug regulators rely on findings largely from RCTs to make recommendations about which drugs to approve.
On Thursday, the prestigious medical journal Nature Medicine published an article authored by concerned epidemiologists and researchers who interrogated studies on ivermectin.
“Many hundreds of thousands of patients have been dosed with ivermectin, relying on an evidence base that has substantially evaporated under close scrutiny,” the authors wrote.
“Several … studies that claim a clinical benefit for ivermectin are similarly fraught, and contain impossible numbers in their results, unexplainable mismatches between trial registry updates and published patient demographics, purported timelines that are not consistent with the veracity of the data collection, and substantial methodological weaknesses.”
Gideon Meyerowitz-Katz, an epidemiologist with the University of Wollongong in New South Wales and a co-author of the Nature Medicine article, says he and his peers scrutinised more than a dozen studies that claim ivermectin is beneficial either as a preventive or treatment for Covid-19.
“Of those studies, we have serious concerns about four that have been made public, and several more which we are still investigating,” he says.
Some of the authors have failed to share data from their research, which Meyerowitz-Katz says “at this point is a very worrying sign”.
“There has only been one retraction so far, but I suspect more are coming,” he says.
Misinformation fuels conspiracy theories
When asked why researchers would make so many mistakes or worse, deliberately mislead, misrepresent and falsify data, he says: “The real question is why none of the groups promoting ivermectin as a mass treatment for Covid-19 did their basic due diligence, because much of the fraud is really not that hard to identify.”
Chaccour believes that pressure on academics plays a role.
“A lot of people are working at entry level and on PhDs, putting in 120 hours a week for less than minimum wage,” he says. “The more you publish and the bigger the paper is, the more recognition the journal gets that publishes it, the closer you are to a more stable lifestyle and career recognition.”
In the case of ivermectin, recognition has come from researchers that cite the papers, pushing the papers up the academic rankings and giving the journals or websites where they are published prominence. But politicians, celebrities and journalists are also promoting the findings.
Slick websites have emerged publishing “treatment protocols” for ivermectin. Some even sell merchandise, including T-shirts carrying the slogan “Covid kills, ivermectin saves lives”.
Chaccour says he has watched in despair as journalists began ascribing a reduction in Covid-19 in Peru to ivermectin rather than strict lockdown measures that were introduced before disease rates fell. This misinformation was helping to fuel conspiracy theories that the medical establishment was deliberately hiding ivermectin because the drug has existed for decades, is cheap to produce, and therefore, not profitable.
In fact, Chaccour says, the chemical companies that produce the ingredients for ivermectin have seen their profits soar. Meyerowitz-Katz says even though ivermectin is off-patent – which means rival pharmaceutical companies can produce cheap generic versions of the drug – the stock prices of two companies that make patented ivermectin products have soared.
Chaccour makes it clear he does not believe these companies are behind the ivermectin push, but says it is wrong for those promoting ivermectin to say the drug was being downplayed because it was not as profitable as new, patented drugs.
“I think for those promoting ivermectin, there’s a level of ignorance and lack of education … there’s a level of mistrust in the government and distrust in science, and there’s a level of ‘I do my own research’ and the pride that comes with that,” he says.
In Australia, the National Covid-19 Clinical Evidence Taskforce develops Covid-19 recommendations for clinicians based on the latest and strongest available evidence. The group does not recommend ivermectin be used outside of randomised control trials and makes the methodology behind its recommendations public.
Despite this, the taskforce’s director Assoc Prof Tari Turner says she and other taskforce members are frequently approached and criticised for not supporting the findings from certain ivermectin studies in their recommendations.
Turner said she was unsure why, despite all of the reputable organisations explaining the lack of evidence for ivermectin in treating Covid-19, people still viewed it as a wonder-drug.
“The taskforce’s job is to find evidence that enables us to determine the effectiveness of ivermectin and other treatments,” she says. “Whereas it seems to me that many of the advocates for ivermectin, and previously, for hydroxychloroquine, are only looking for evidence that shows it’s effective.”