“You are not a horse. You are not a cow. Seriously, y’all. Stop it,” read a recent viral tweet warning readers away from using a certain medication to treat Covid-19. The tone of affectedly folksy condescension would be expected from any of thousands of Twitter-addicted progressive journalists, but less so from the official account of the United States Food and Drug Administration. Perhaps even more surprising, the tweet linked to a warning advising readers not to take a drug, ivermectin, that has been used in humans for decades and is a standard Covid-19 treatment in much of the world.

The FDA’s framing has been echoed by a rash of media articles warning that ivermectin is ineffective and fit mostly for animals, typically citing the FDA’s public statements as the main evidence of inefficacy. A recent story in the Washington Post, for instance, noted in the headline that an Arkansas prison doctor had given inmates the “livestock drug ivermectin,” even “despite FDA warnings.” NPR noted that the popular podcast host Joe Rogan had attempted to treat his own case of Covid-19 with “a deworming veterinary drug that is formulated for use in cows and horses” that “the FDA urges people not to use.” (Both articles eventually noted, less prominently, that the drug had human uses, though NPR mentioned its use only as a topical treatment for head lice.) NBC’s story on Rogan called ivermectin “typically used on livestock” in the first paragraph, “not an anti-viral drug” in the third, and “widely discredited” in the headline—adducing as evidence only that “the U.S. Food and Drug Administration last month urged people to stop believing misinformation claiming the livestock treatment would help cure Covid.” A New York Times story dismissed evidence for the drug with the statement “Ivermectin Won’t Treat Covid 19 But Demand For Drug Surges,” and its discussion of scientific evidence on the drug focused only on negative studies, but the story authors at least acknowledged that the drug was commonly used in humans.

To be fair, a few Americans who couldn’t obtain human ivermectin have, in fact, tried to self-medicate with veterinary formulations—provoking a slew of reports about overwhelmed poison-control systems and ER departments that spread wildly across liberal Twitter, often with mocking commentary on the stupidity that must be required to take animal medicine. Many of these stories have also proved to be huge exaggerations. One widely circulated Associated Press report alleging that livestock ivermectin caused 70 percent of calls to Mississippi poison control—the real figure is 2 percent—seems to have stemmed from a misreading of a poorly worded bulletin from the state Department of Health. In any case, the story noted in its seventh paragraph, “most callers have had mild symptoms.” According to national data, while poison-control calls for ivermectin did increase in late August, they remained quite low in absolute numbers, peaking at a few dozen per day. One story reprinted in Rolling Stone alleging that ivermectin poisoning had overwhelmed hospitals in Oklahoma seems a near-complete fabrication, or, at best, wild extrapolation from the article’s one source.

Another story from NBC reported that a study had found that ivermectin “causes sterilization in 85 percent of men.” Such an enormous undiscovered side effect of a common drug was implausible enough even without consulting the underlying study, published in 2011 by four Nigerian researchers in an obscure journal whose publisher’s homepage includes a bizarre essay on buying CBD oil. Those researchers attributed the 85 percent figure to a different study that supposedly appeared in another, now defunct Nigerian journal in 2002—a year before the journal began publication, according to an online index that lists no articles with a relevant title in any of its seven volumes. Links to the story, including several posted by high-profile liberal Twitter users, racked up tens of thousands of posts and retweets, many with gleeful comments about the salutary effect that ivermectin would have on the gene pool.

The media’s recent reporting on ivermectin is a fitting sequel to their reporting on hydroxychloroquine near the beginning of the pandemic—but not, as received opinion would have it, because both are tales of red-state yokels duped into taking poisonous phony remedies. As in the earlier case, media coverage of ivermectin exemplifies how the liberal political class’s bias, and its confusion of respect for science with blind trust in a scientific establishment, impairs their skepticism and their capacity to appraise complex scientific questions.

Ivermectin is one of several derivatives of a family of compounds first isolated in the 1970s from soil bacteria in Japan. The compounds are highly toxic to invertebrates but have few effects on mammals, making them excellent treatments for many diseases caused by parasitic worms. Though ivermectin is more commonly used in livestock in First World nations where human parasites are rare, it is widely given to humans for internal use elsewhere. Distribution of ivermectin in tropical Africa has virtually eliminated diseases such as river blindness, a success that won the drug’s discoverers a share of the Nobel Prize in Medicine in 2015.

Ivermectin, then, has long been used in humans—and it is entirely reasonable to think that it could be effective against Covid-19. It may be surprising that an antiparasitic medication might work against viruses, but such surprises are common in medicine: as another example, the psychotropic drug fluvoxamine, used to treat OCD and depression, has shown positive results against Covid-19 in multiple trials, including one large international collaboration. Ivermectin was shown to have antiviral effects in laboratory settings in 2012, when one study found that it protected cell cultures from infection by flaviviruses, which include the viruses that cause yellow fever and dengue. Interest in ivermectin as a Covid-19 treatment was sparked by a study at Monash University in Australia, which found that the drug could virtually eliminate SARS-CoV-2 from cell cultures within two days, albeit at very high concentrations.

Though ivermectin has some side effects—dubious Nigerian studies aside, some legitimate research in rats suggests that several weeks of regular exposure may impair male fertility—it is relatively safe. One recent study examining data from VigiBase, a large international system for monitoring drug side effects run by the World Health Organization, found only 667 serious possible reactions to ivermectin, many of the worst of which were reactions that occur as the body rids itself of dead parasites, such as Mazzotti reactions and certain encephalopathies. (Adverse reactions to veterinary ivermectin in humans, as the FDA’s own statement acknowledges, are likely the result of inactive ingredients or dosage miscalculations.)

Studies in cell cultures, though, can establish only that a drug might work; to decide that it does work requires human studies. The evidence base in this regard is ultimately inconclusive but suggests that ivermectin could provide a meaningful benefit.

Media attention to ivermectin is largely thanks to a group of doctors who call themselves the Frontline Covid-19 Critical Care Alliance. Pierre Kory, one of FLCCC’s founders, has advocated ivermectin treatment in several high-profile public appearances, including testimony before the Senate Homeland Security Committee last December and a more recent interview in June on the popular podcast DarkHorse, hosted by Bret Weinstein and Heather Heying. FLCCC puts out continually revised protocols that include ivermectin as a main component, as well as other drugs with varying degrees of empirical support.

FLCCC’s exact protocols have never been tested in randomized trials, but there are some weaker forms of evidence in their favor; many other doctors who use FLCCC or similar protocols have claimed vast improvement over typical rates of death and hospitalization. Overseas, influential doctors such as the chairman of the Tokyo Metropolitan Medical Association have called for widespread ivermectin use, and the drug is a standard treatment in much of Latin America, among other areas.

A few epidemiological observations show potential effectiveness of ivermectin, though deducing causality from such observations is fraught. For instance, Covid-19 has largely spared Central Africa, where the drug is widely administered for parasitic diseases, even as recent waves have struck other tropical areas that had earlier seemed immune. In India, the horrendous Covid wave from April and May has dwindled to insignificance in all states but Kerala, which now contains about two-thirds of India’s total new Covid cases and only 3 percent of the nation’s population. This difference may have other contributors such as Kerala’s mass testing regime, but Kerala is also one of only a few places in India where ivermectin is not a standard treatment: the state health department recommended it only for high-risk patients in treatment guidelines in April and removed it altogether in August.

The evidence from more formal studies, though, is conflicted. Several studies have shown substantial positive results, but reason exists for skepticism. Most studies are small, often with only a few dozen subjects, and have large error bars. The largest recent trial, a multinational collaboration called the TOGETHER Trial, tested several promising repurposed drugs on outpatients and found only statistically insignificant benefits for ivermectin: a 9 percent reduction in hospitalization and 18 percent reduction in death, both with error bars that extended well across zero. (Ivermectin advocates have claimed that TOGETHER used too low a dose, but a smaller study also widely cited by advocates claimed good results with even smaller doses, on hospitalized patients with more severe disease.)

Ivermectin research, finally, may involve a surprising amount of outright fraud. A few researchers and journalists have found clear evidence that at least three studies frequently cited in support of the drug—one since formally retracted by the journal that published it—are likely based on fabricated data.

Still, given the drug’s relatively low risk profile, it may be reasonable to try ivermectin against Covid-19 despite the ambiguous evidence of benefits. And in any case, the sneering descriptions of the drug as an assuredly useless livestock de-wormer and the wild exaggerations of its dangers—both close parallels with the news coverage of hydroxychloroquine in spring 2020—cannot be justified.

Liberals have no monopoly on gullibility or lazy journalism, but the biased coverage of ivermectin springs from one of the worst pathologies of liberal discourse in particular: conflation of respect for science with fealty to established scientific institutions. A “pro-science” disposition has long been integral to American liberals’ self-conception (a ubiquitous yard sign reads, in part, “In this house, we believe science is real”); it grew especially strong during the George W. Bush years as a reaction to the administration’s stance on global warming and alliance with the religious Right.

But most Americans are scientists neither by training nor by temperament, and “pro-science” politics usually calcifies into blind trust in a few politically congenial authorities—such as universities and government health agencies, which have enjoyed high levels of liberal confidence throughout the pandemic despite such actions as reversing longstanding advice on face masks based on a dubious judgment call.

Conflating science with the scientific establishment not only corrodes the capacity for skepticism but also helps questionable or corrupt actions by authorities escape scrutiny. The hullabaloo over ivermectin poisoning, for example, far exceeds the attention given to another questionable treatment pushed not by right-wing hucksters but by the FDA itself: remdesivir, an antiviral produced by the pharmaceutical giant Gilead Sciences that is still the only Covid-19 treatment with full FDA approval.

The FDA’s approval of remdesivir in October 2020 was based on only three trials, one neutral and two showing only moderate shortenings of hospital stays. A week before the approval, a far larger trial sponsored by the WHO had found that remdesivir did not reduce mortality, leading the WHO to advise against the drug in November. (The New York Times report on the WHO trial, incidentally, gave ample space to a fair presentation of criticism of the trial from defenders of remdesivir, a marked difference from the tone of most recent ivermectin coverage.) Furthermore, remdesivir seems to cause significant harms to the kidneys in many cases: a “disproportionality analysis” of VigiBase, for instance, found that reports for remdesivir were 20 times as likely to mention kidney failure as reports for other Covid-19 drugs. The FDA’s full approval of remdesivir contrasted with its summary dismissal of ivermectin suggests, at the least, a double standard.

The oddity of the FDA’s remdesivir approval received some mainstream coverage, but it came nowhere near the level of media saturation reached by the reports of Mississippians taking horse de-wormer. It’s not hard to understand why: the horse de-wormer stories gave some readers a delicious opportunity to feel smugly superior to their political enemies—a temptation that few of us find easy to resist. But the tale of remdesivir presents a more threatening specter, which journalists and politics junkies would do well to confront: the possibility that a scientific authority might be wrong.

Photo by Soumyabrata Roy/NurPhoto via Getty Images


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