Related topics

False claim spreads about Japanese ivermectin study, despite correction

February 2, 2022 GMT

CLAIM: A Japanese study “says ivermectin is effective against Omicron in phase III trial.”

AP’S ASSESSMENT: False. While scientists continue to conduct research into the drug’s use against COVID-19, the finding being cited refers to pre-clinical research — not a “phase III trial,” which involves testing the drug on humans.

THE FACTS: Social media users are sharing false information about a Japanese company’s research into using ivermectin to treat COVID-19, after a news agency published an erroneous headline that it soon corrected.

Reuters published the inaccurate headline on Monday, saying: “Japan’s Kowa says ivermectin effective against Omicron in phase III trial.”

The story made it appear that the results broke significant new ground. Phase III clinical trials are conducted on people. But the research done by Kowa Co. Ltd. was conducted in a lab.

The report was based on an announcement from Kowa that said ivermectin showed “antiviral” effects against omicron and other variants in pre-clinical research.

Kowa said in a statement to The Associated Press that “the press release announced that ivermectin was effective against Omicron strain” in an “in vitro study (i.e. non-clinical study), not in the clinical study.” The company said it was now conducting a phase III study on volunteers to further evaluate the effectiveness of ivermectin in treating COVID-19, but that it’s in progress and the results aren’t yet available.

Reuters soon corrected its story and acknowledged the mistake. Its current headline reads: “Ivermectin shows ‘antiviral effect’ against COVID, Japanese company says.”

But social media accounts continue to share the falsehood.

Ivermectin is approved in the U.S. in tablet form to treat parasitic worms as well as a topical solution to treat external parasites. The drug is also available for animals.

The U.S. Food and Drug Administration has not authorized ivermectin for use in preventing or treating COVID-19. And a National Institutes of Health panel on COVID-19 treatment guidelines has said there is “insufficient evidence” to “recommend either for or against the use of ivermectin for the treatment of COVID-19.”

The AP has previously reported that a 2020 study in Australia found ivermectin inhibited the replication of the coronavirus, SARS-CoV-2, in a laboratory setting.

But pre-clinical research in labs isn’t the same as proving a drug works in humans.

Dr. David Fajgenbaum, an immunologist at the University of Pennsylvania who directs a database tracking research into treatments for COVID-19, said that showing a drug to be effective in lab tests on cells is a “starting point.”

Fajgenbaum said there have been 25 randomized controlled trials — a gold-standard for research — studying ivermectin as a treatment for COVID-19. The trials have collectively involved more than 2,000 patients, he said, and the results have been mixed.

“In my opinion, there’s a possibility of benefit, but given that so many trials have been done, if it clearly was effective you would expect that the majority of trials would show that it was effective,” Fajgenbaum said. “If something works, then it should be a rare occurrence that a trial is done and it doesn’t show that it works.”

Still, there are ongoing trials continuing to assess the use of the drug, Fajgenbaum added.


Associated Press writers Audrey McAvoy in Honolulu, and Sophia Tulp in Atlanta, contributed to this report.


This is part of AP’s effort to address widely shared misinformation, including work with outside companies and organizations to add factual context to misleading content that is circulating online. Learn more about fact-checking at AP.