Institut Pasteur Preclinical Study: Ivermectin a Powerful Immunomodulatory Drug Targeting SARS-CoV-2

Institut Pasteur Preclinical Study: Ivermectin a Powerful Immunomodulatory Drug Targeting SARS-CoV-2

A prestigious global research institute based in France has published a preclinical study in EMBO Molecular Medicine revealing that ivermectin is associated with a reduction in COVID-19 symptoms. Yet even after dozens of studies showcasing such results in real-world scenarios, the World Health Organization (WHO) has yet to embrace the opportunity of the drug for low-and middle-income countries (LMICs). Institut Pasteur’s Jean-Pierre Changeux suggests the drug acts on the nicotinic receptor, leading to what undoubtedly will fuel an interesting debate on the topic. In a comprehensive preclinical study involving hamsters, the study team concluded that ivermectin represents a powerful immunomodulatory drug, implying that it could help the world in its fight against the COVID-19 pandemic. The study results reveal that the anti-parasitic drug ivermectin prevents clinical deterioration, reduces olfactory deficit, and limits the inflammation of the upper and lower respiratory tracts in the study animals. The investigators recommend consideration of the drug as a means to combat COVID-19.

The Challenge & Opportunity

A devastating pandemic continues with emergent new variants and a growing death toll while vaccines, while effective and seemingly safe, are distributed in a way that could be considered anything but equitable. Low-and-middle-income countries (LMICs) struggle to vaccinate even a fraction of the population as a market-based system directs product to the highest bidders.

Meanwhile, over 62 ivermectin studies (randomized controlled trials, observational and case series) have been conducted around the world with overwhelmingly positive outcomes. A few meta-analyses have added to the promising evidence yet regulatory authorities, apex research agencies, and global groups such as the World Health Organization (WHO) while monitoring the trends seek to act in ways to subvert the progress and potential for the generic repurposed drug.  TrialSite has observed a directed, concerned, and orchestrated misinformation campaign against ivermectin that includes a prominent producer of the product, Merck. The American pharmaceutical company also was paid $356 million by the U.S. government to develop its own COVID-19 antiviral drug called Molnupiravir—and just months later, secured a $1.2 billion public procurement commitmentTrialSite suggests liberal government funding has led to a culture of public financial dependence during the pandemic, corrupting markets and outcomes.

TrialSite has been on record that WHO has failed its role as a global authority and allocator of funding and treatments to help member nations. If vaccination distribution is any measure, while the WHO blames the pharmaceutical companies, it was actually their responsibility for more equitable distribution. That hasn’t happened. Yet, WHO has in parallel resisted mounting evidence associated with ivermectin as a possible low-cost measure to help fight the pandemic. 

Regardless of WHO’s disapproval of the drug, much success has been associated with ivermectin. TrialSite has chronicled study after study, from Bangladesh and Uttar Pradesh, India to Mexico City and even Broward County, Florida, where physicians and clinical investigators report on impactful results. TrialSite reported that because of WHO’s recalcitrant stance, a collection of lawyers out of Bombay announced a lawsuit against the WHO and its chief scientist, Soumya Swaminathan, accusing them of avoiding the mounting evidence in favor of the drug.

The Study Results

Now a prominent, globally focused, French, non-profit private foundation introduces compelling new information about ivermectin. The authors declare, “variants that jeopardize the efficacy of current vaccines create an urgent need for a comprehensive understanding of the pathophysiology of COVID-19, including the contribution of inflammation to disease..”

The authors summarized that the pandemic also necessitates a “search for immunomodulatory drugs that could improve disease outcome.”  In a preclinical hamster study, the scientists at the Pasteur Institute showcased that the anti-parasitic drug ivermectin prevents clinical deterioration, reduces olfactory deficit, and limits the inflammation of the upper and lower respiratory tracts in SARS-CoV-2-infected hamsters.

The preclinical investigators in France reported that the drug didn’t affect viral load in the infected animals’ airways. Moreover, after conducting transcriptomic analyses of infected lungs, scientists there report that ivermectin dampens type 1 interferon responses while modulating a number of additional inflammatory pathways. Noteworthy, they reported that ivermectin “dramatically reduces the Il-6/Il-10 ratio in lung tissue and promotes macrophage M2 polarization, which might account for the more favorable clinical presentation of IVM-treated animals.”

The French scientists concluded, “This study supports the use of immunomodulatory drugs such as ivermectin, to improve the clinical condition of SARS-CoV-infected patients.”

Principal Investigator Point of View

The researchers were quoted in the French press commenting on the significant positive results yet declaring that the effects seem to be immunomodulatory rather than antiviral in nature, reported Guilherme Dias de Melo, an epidemiologist and study co-author. Corresponding author Hervé Bourhy considers these “results provide significant progress and […] pave the way for development…for better treatment against COVID-19 in humans.”

Institut Pasteur

Founded in 1887, the Institut Pasteur has researched infectious diseases for over a century. This worldwide biomedical research organization based in Paris was the first to isolate HIV, the virus that causes AIDS, in 1983. Over the years, it has been responsible for discoveries that have enabled medical science to control diseases from diphtheria and tetanus to tuberculosis and influenza to yellow fever and plague. Since 1908, ten Institut Pasteur scientists have been awarded the Nobel Prize for medicine and physiology.

Lead Research/Investigator

Herve Bourhy, Lyssavirus Epidemiology and Neuropathology Unit, Institut Pasteur, Paris, France, Corresponding Author

Jean-Pierre Changeux, Neuroscience Department, Institut Pasteur, Collège de France, Paris, France

Call to Action: To review the other authors or read the study, follow the link


  1. Great news…for hamsters.

    Note: Six days ago, I was (once again) exposed (for > 2 hrs.) to someone who shortly thereafter became symptomatic and tested positive for COVID-19. I am waiting for a local pharmacy to fill my Ivermectin prescription (obtained from an online physician who wrote the script based solely on my claimed exposure). The point being that I’m not a naysayer — but, I would really like some definitive proof that Ivermectin is effective in treating COVID-19.

    But, hey — in the meanwhile, I am gonna be totally worm free!

    1. “I would really like some definitive proof that Ivermectin is effective in treating COVID-19. ”

      Me too. But I do not intend to die waiting for it.

      We are so early into this. “definitive proof” might not come for years, if then.

      Look at the history of USA regulatory agencies. I see them as reeking with corporate influence.

      Looking at FDA specifically, they gave Big Tobacco a pass for decades. They continue to give Big Agra and the processed food industry a pass on “foods” that are proven to kill surely if slowly.

      Dr. Robert Lustig has referenced this deeply in his new book, released in May 2021 and he names names. In addition to being a pediatric endocrinologist, he has a master in legal studies.

      He sites a metadata study of 60 trials related to the potential harm of adding sugar to processed foods. That metadata study found the evidence was “inconclusive”. Then there was a reanalysis, based on funding of the studies. Seems ALL 26 studies sponsored by the food industry found no link to sugar being harmful. On the other hand, 33 of the 34 remaining studies that were independent did find sugar harmful. Only 1 of these independent studies found the evidence to be “inconclusive”.

      The processed food conglomerates poisoned the pool of peer reviewed literature just as we are witnessing Big Pharma doing today with non-patentable therapeutics like ivermectin.

      Consider that “definitive proof” for ivermectin, depending on the definition of that, might never come. We will have to use our best abilities to filter out the sham studies that are designed to fail and/or are created ignoring the evidence we do have available as to levels and frequencies of dosing.

      I think you made a good call to get your hands on ivermectin. A good risk/benefit decision IMO. Like, what will it hurt, even at the outrageous prices it is garnering in the USA.

    2. But there is a great deal of definitive proof. If you don’t like the RCTs and meta-analyses, take a look at before and after IVM use in large population studies such as Peru, Mexico, Uttar Pradesh and other places around the world.

      1. @BT1 The India State of Tamil Nadu didn’t allow Ivermectin, but its COVID-19 cases and deaths fell in line with those States that authorized Ivermectin use.

        I have little doubt that IVM works. But questions remain as to how well, optimal dose, confounding factors, etc.

        Regardless, I’m not going to stake my life on waiting for “definitive proof.”

        1. Do you have references supporting the “fact” that “Tamil Nadu … COVID-19 cases and deaths fell in line with those States that authorized Ivermectin use”?

          “This is what happened to cases in the areas that chose Ivermectin:

          Delhi : ¯ 97% [28,395 to 956]
          Uttar Pradesh: ¯ 95% [37,944 to 2,014]
          Goa: ¯ 85% [4195 to 645]
          Karnataka: ¯ 60% [50,112 to 20,378]
          Uttarakhand: ¯ 87% [9,642 to 1,226]

          Observe what happened to those areas that DID NOT choose Ivermectin:

          Tamil Nadu ­ 173% [10,986 to 30,016]
          Odisha ­ 50% [4,761 to 7,148]
          Assam ­ 240% [1,651 to 5,613]
          Arunachal Pradesh ­ 656% [ 61 to 461]
          Tripura ­ 828% [92 to 854]

          1. @CoS I don’t know if the following links will resolve correctly using your web browser. Assuming they do, then it’s observed that Tamil Nadu experienced the same sort of spike as did Uttar Pradesh. It’s also observed that Uttar Pradesh has fallen further. from the peak, but Tamil Nadu has fallen, presumably without Ivermectin intervention.

            The question is whether Ivermectin caused the difference. It may be so — but, correlation does not equal causation, and in my experience, this evidence, while it may be convincing to many, it would not, imho, convince a judge (assuming that the issue before a court were whether Ivermectin is a safe and effective therapy against COVID-19).

            It’s a common belief that the burden of proof necessary to validate a scientific hypothesis is “falsifiability” — and that this burden is far higher than the three burdens of proof required in a U.S./common law court: preponderance of the evidence (>50%); clear and convincing evidence (>75%); beyond reasonable doubt (>95%). In practice, however, it seems to me that scientific research publications rarely adhere to their purported standard of proof — whereas courts nearly always do (at least I find this true where the judge is highly competent — and there are plenty of low-competency judges (imho). Which reminds me of a lawyer joke:

            Q: What do you call a lawyer who received all Cs in law school and failed the bar exam three times before finally passing?

            A: Your honor!


            Tamil Nadu –
            Uttar Pradesh –

          2. @Ken.Kaplan.Esq.
            India’s Ministry of Health and Family Welfare revised its guidelines on April 28 recommending ivermectin. Uttar Predesh was reported to be using ivermectin prior to that, with good results.

            And I ask, why then the exponential serge after April 1? (Some relate that to the surge of workers fleeing Mumbai region where the double variant Delta was exploding and returning, contaminated, to Uttar Predesh)

            According to those links,
            Uttar Predesh (pop. 235M) peaked on April 24 at about 38,000 cases/day Then fell rapidly to June 1, with 1200 cases/day. Any by July 15, their 7-day average was only 93/day.

            In contrast, Tamil Nadu (pop. 78M (1/3 that of Uttar Predesh)) the cases kept steadily rising until reaching over 36000 cases on May 21. Then a more gradual drop began to July 15 with a 7 day average of 2678/day, 30 times the current number in Uttar Predesh and 90 times the per capita rate.

            Question i would have is, once seeing the precipitous drop in Uttar Predesh, did doctors in Tamil Nadu start ignoring their local health advisory and start using ivermectin more? Maybe one day someone will provide the stats for that.

            Regardless, the surge only lasted 60 days in Uttar Predesh, while it still rumbles in Tamil Nadu more than 90 days later.

    3. Ken
      At least you’re doing something.
      If you follow CDC. NIH, and WHO guidelines, you are to quarantine at home, doing nothing for treatment until you either get better, or become so sick that you need hospitalization where, worst case, they drive a tube down your throat, giving you a 30% chance of survival.
      That’s akin to having a bad cut on your hand become infected, doing nothing until it turns to gangrene, and then seeking help.
      This is in (what used to be) one of the most advanced countries in the world.
      I weep for my country…….

    4. Update: My Ivermectin prescription was filled for $3.00! (25 3 mg tablets).

      Cheap insurance!

      Cost of online doctor visit: $0.00 USD (but, I made a $100.00 “donation,” despite the fact that the IRS will view the payment as taxable income to the physician; perhaps the doctor, if s/he reads this, will decide to make a “donation” to my favorite tax lawyer, for writing a “legal” prescription).


    1. I am combining the two; I believe they’re deeply synergistic. I’ve been prophylaxing weekly with IVM (work in a health care setting) since December 2020; and have been on LDN since 2016 for allergies. I feel great and have had one mild bout of cold or flu in those 5 years.

      I noticed that the FLCCC has added LDN to their long-hauler protocol (

      I’m waiting for this study of LDN for Covid to report results:

      I think that because of LDN’s calming and optimizing effect on the immune system, and its tendency to switch the adaptive response from Th2 (humoral, antibody) to Th1 (T-cell mediated), it should prove to be a potent additional tool against the progression to severe, late-stage Covid. I believe that the primary underlying mechanism in severe Covid is the triggering of autoimmunity due to the very high degree of human peptide mimicry in the spike protein.