The intent of this article is to affirm to military providers and medics that the JTS Envenomation CPG and Antivenoms it suggested are efficient and data backed. We remind medics to be cautious of medical claims with no supported evidence.

Recently, The Guardian & TBIJ articles collaborated with a scientist (Not Doctor), Juan Calvete, who tried to make false statements with no proof about Polyserp/Inoserp 500 and the US Military using it to protect their service members. They spewed this venom by suggesting experiments that allegedly showed that this antivenom has less protein in a vial, which they somehow assumed that protein content in vials equates to how much it works in humans. Protein amount is not relevant to the impact in a human body. Medication can do more with less, depending on the potency, affinity or avidity. Their imaginary conclusion goes against the strong published observational data of this working in humans across Africa for the past decade, cited below. You don’t refute a medical intervention that Doctors have been using to save human lives (clinical data) by saying you tested it in a lab (Pre-clinical data, if it was published) and thinking that equates to a human body.
We recently published an article on how to read research, so you should be able to appreciate the data below. We can not show you data from The Guardian, TBIJ or Juan Calvete because they did not cite any. You will notice there were no financial ties disclosed in the Guardian or TBIJ articles, or denials of any, which comes with a risk for manipulation and bias. They did not offer any alternative product besides the “PANAF-Premium” which has mostly animal data (source), and clinicians should avoid reliance on animal models since pre-clinical data doesn’t always translate to human efficacy. These lies are detrimental to the capabilities that support thousands of US Service Members deployed globally. These false assumptions could create a public health crisis through undermining evidence based medicine with random comments that could lead to knee jerk reactions.

If you need more explanation, we will provide rebuttals for each segment below.

False claim #1: “The US Army spent nearly $1m last year on two drugs that appear to have undergone no independent testing for safety or effectiveness, the Bureau of Investigative Journalism (TBIJ) can reveal. TBIJ has tested the civilian version of one of the drugs and found it to be alarmingly weak. Neither the army nor the government agency that recommended the military drug has tested it to verify the manufacturer’s claims… Instead, he was sent three studies that purported to show the “safety and efficacy” of Polyserp but in fact related to the other drug, Inoserp. David Williams, a leading snakebite expert at the WHO, said extrapolating data from one product to another “is not consistent with the WHO guidance”.

There is plenty of peer reviewed observational single arm data on Inoserp below.
The “civilian version” of the drug is not weak and there is no data to support this claim, and no citations or studies in their article.
There are few RCT’s for antivenom because it can be unethical to give someone dying of snake envenomation a known placebo when antivenom is known to work, but can be done comparing various dosing or against other antivenom, assuming supplies are plentiful enough to accomplish the latter. For example, one of the last African Antivenom RCT was in 2010 on “EchiTAb”, although those cover limited species and require refrigeration.
The false information starts with the non-commital “appears to have” but does not take into account that Polyserp is able to use Inoserp 500 data. Drugs that are similar enough do not need to undergo further testing, there are many examples of medications that did not need entire studies to do what is already being done. This is easily disproven, as the WHO’s own 2018 document “Launch of WHO Assessment and Listing of Snake Antivenoms,” explicitly advises antivenom companies on page 4 that “safety data from other antivenoms made by the manufacturer using the same product platform may be considered as supportive data for review.”(World Health Organization 2018). The use of data from Inoserp to support the introduction of Polyserp 500 (an antivenom made by the same manufacturer using the same product platform with higher neutralization and expanded coverage) is therefore wholly consistent with WHO guidance. Additionally, Inosan and Polyserp voluntarily engaged with the FDA Center for Biologics Evaluation and Research prior to commercializing the product to discuss the best strategies for doing so, and were advised that the best path was to utilize data from Inoserp to support the introduction of Polyserp.

  1. Real life condition evaluation of Inoserp PAN-AFRICA antivenom effectiveness in Cameroon – ~447 patients, one of the largest peer-reviewed antivenom studies in Sub Saharan Africa
  2.  A Clinical Review of a Polyvalent F(ab’)2 Antivenom (InoserpTM PAN-AFRICA) in the Management of Snakebite Envenomation in Sub-Saharan Africa: Clinical Studies and Actual Use since Its Introduction in 2012: ~200,000 vials in 10 years across 20+ countries and 4 studies. 
  3. Evaluation of a new polyvalent antivenom against snakebite envenomation (Inoserp® Panafricain) in two different epidemiological settings: Northern Benin and Maritime Guinea
  4. Evaluation of the efficacy and tolerance of Inoserp® Panafricain in Senegal
  5.  Sérothérapie antivenimeuse au Mali : expérience du centre de santé

False Claim #2: The drugs are not among those that have been assessed and recommended by the World Health Organization (WHO) and because they are not intended for use in the US, they have not been fully assessed by the Food and Drug Administration (FDA). Both drugs are versions of a snakebite antivenom called Polyserp and cost the army a combined $880,000 last year. One covers Middle Eastern, North African and Central Asian regions, and the other covers sub-Saharan Africa – where a recent TBIJ investigation revealed a “wild west” of antivenoms that are badly made, marketed and regulated.

The United States is no longer a part of the WHO, and WHO has no bearing on what the US Military chooses to acquire and provide in order to give the best care to its deployed soldiers. The US Military may even adopt products such as whole blood or freeze dried plasma ahead of even FDA approval to ensure it saves lives earlier, which paves the way for civilian EMS to adopt the capabilities and save additional lives both at home or internationally. In this case, Polyserp capability enables thousands of soldiers deployed across over dozens of countries to perform operations without worrying about lethal snake bites. The JTS guidelines ensure tens of thousands of service members in over a hundred countries know the best way to treat many conditions beyond snakebites. To suggest the US Military would acquire something without the service members best interest in mind is nothing short of profane. There is no citation for the cost spent in their article.

With regards to the comment of Polyserp lacking US FDA approval, ~19 of the ~22 first line products recommended in the CPGs do not have US FDA approval because they are made for exotic snakes which are not native to the United States. The only CPG recommended antivenoms with FDA approval are the North American antivenoms for viper bites (CroFab and Anavip) and coral snakes (NASCA) because they predominantly affect US populations, are stocked in US hospitals/administered by US providers, and therefore fall under jurisdiction of the United States FDA. Inoserp and Polyserp, made by Inosan Biopharma in Mexico, are created with the highest GMP standards from COFEPRIS. Mexico has some of the leading global antivenom facilities, which were emphasized after the President of Mexico’s son had a near fatal scorpion envenomation. Eventually, Mexico would even produce scorpion antivenom for the United States and be quickly FDA approved.
Still, the FDA recognizes that foreign antivenom manufacturers have no incentive to conduct expensive clinical trials in the United States on bites by non-native exotic species which occur very rarely in the US (zoos, private keepers, venom labs, etc). The FDA also recognizes the need for US medical providers to have channels which provide legal access to procurement, storage, and use of these medications within the continental United States. As a result, FDA created the BB-IND pathway specifically to facilitate the availability and use of non-FDA approved foreign antivenoms by US providers when circumstances require them. FDA approval is not mandated for exotic snake antivenom and obtaining it would require large-scale U.S. clinical trials in a population that sees too few African envenomation cases to facilitate such trials. The BB-IND pathway therefore supplies the lawful mechanism for U.S. use whenever a clinical situation requires it. It is worth noting that Polyserp is, as far as these authors are aware, the only foreign antivenom manufacturer to have invested in engaging with the FDA to explore the process of FDA approval to facilitate greater CONUS availability for US military medical providers.

While there is a “wild west” of antivenoms, the JTS guidelines were reviewed and cited to include recommendations on navigating through that process. It’s easy to see that JTS does not have brand loyalty if one looks through any of their guidelines, only loyalty to doing what is best for the service members. If at any time it is felt an intervention could be added or removed, the guidelines can be easily changed as data and medicine changes. JTS is also reachable for DoD providers and medics looking for other solutions within their area of operations. They are also always open for considerations of future updates and different viewpoints through contacts on their website.

False Claim #3: The company promoting the sub-Saharan African version of Polyserp (called Polyserp-P) demonstrates the drug’s credentials with studies relating to another drug, Inoserp Pan-Africa. Both drugs are from the same manufacturer. But Inoserp is itself hugely problematic. The sub-Saharan African version of that drug featured in TBIJ’s recent investigation into useless antivenoms, where testing revealed that, compared to its competitors, a vial of Inoserp contained a fraction of the active ingredient needed. Test results suggested that more than 70 vials would be needed to treat bites from certain snakes. One Kenyan doctor with more than two decades’ experience treating snakebite told TBIJ he refuses to use Inoserp. The drug failed in a bid to get WHO approval in 2017.

False, reference above studies. Baseless claims without one study cited or experts named, and even one named “expert” wouldn’t be grounds to stand on. “Test results suggested more than 70 vials” is based on imaginary lab data which does not translate to humans. Imagine saying Fentanyl is weaker than Morphine because it has micrograms instead of milligrams. It’s basic elementary science to understand that if something is more potent, it needs less to get the job done. Additionally, due to hierarchy of studies, this pre-clinical lab data, if it ever saw the light of day, would fall far below actual data on real humans cited under #1. However, this data was never published so this is a baseless assumption. This is equivalent to non-doctors testing Ibuprofen in a lab then suggesting Doctors stop using it on humans when it is already shown to be working. How molecules behave in a body is not a great extrapolation for the receptors, processes and environments they will encounter in the human body.

If you read our article on how to approach studies, you would see that this information does not pass the sniff test for research, and it isn’t even published therefore it is hearsay. Scientists do not conduct science by talking about what they can’t prove, and clinicians do not practice medicine or recommend others do the same based on hidden studies in labs. At a time where medicine and science is fragile, it is harmful to make accusations.

False claim #4: A spokesperson from Inosan Biopharma, which produces both drugs, and Polyserp Therapeutics, which markets Polyserp, said the companies questioned the validity of the testing done by TBIJ. (The testing methodology follows WHO guidelines for test tube assessment of snake antivenoms.) The spokesperson said: “Polyserp-P is an updated version of Inoserp with higher potency and expanded indication exclusively produced and approved for distribution to US military customers.” Inosan Biopharma and Polyserp Therapeutics also said that “both Inoserp and Polyserp have proven effectiveness in robust pre-clinical and clinical trials” and that a panel of independent experts reviewed the clinical, preclinical and safety data. However, neither company responded to TBIJ’s repeated requests to provide evidence to back up these claims. The lack of clarity raises questions. If the two drugs are effectively the same, then the army is buying something shown to be poor quality. If Polyserp is a different and more potent product, why are ordinary people in sub-Saharan Africa not able to access it?

Polyserp-P is an updated version of Inoserp with higher potency, so they admitted and destroyed their own argument about protein amount equating to effectiveness allegations. “In vitro preclinical immunological cross-reactivity testing alone is NOT an adequate measure of antivenom efficacy.” – WHO Technical report series, Page 232. They were provided with studies, we have email receipts available upon request to show that the above cited data was ignored. We cited the studies above in this article for anyone to read and draw their own conclusions, so there is no reason that any clinician could not have easily found them.

As far as ordinary people in sub-Saharan Africa not having access to the more potent Polyserp product or the logistics and finances of antivenom in general, this is a multifaceted discussion irrelevant to original claims. “The US Military is one of the largest players in global health. The relationship between snakebite NGO’s such as ASF and US military medical experts began due to the crossover between prolonged field care, wilderness medicine, and snakebite treatment in the developing world and has been one of the most impactful relationships benefiting patients in underserved regions since the inception of the Asclepius Snakebite Foundation in 2018. Key innovations such as portable capnography and low-resource tools for diagnostic and monitoring purposes that are used daily in ASF clinics came from experienced and passionate medical providers in the SOF community. WHO’s own estimates suggest that only 2.5% of patients in Africa who require antivenom receive it, but the contributions made by the US military to our non-profit efforts have dramatically improved our ability to save lives and limbs overseas, particularly in complex critical care scenarios such as mamba envenomations. It is highly inappropriate for individuals who are provoking a preventable public health emergency to criticize the US military for any actions related to snakebite, where they have arguably gone above and beyond to support humanitarian efforts in addition to doing what is needed to ensure the health and safety of their own troops”, – Jordan Benjamin, founder of Asclepius Snakebite Foundation and first author of the clinical practice guidelines.

False Claim #5: Antivenom experts have described the purchase as “naive” and “surprising”. The findings raise questions about the military’s protocols for evaluating critical medicine before deploying it to troops.


No experts were cited. Nobody said that. You can not say “Antivenom experts” without naming names. Additionally, the military’s protocols for evaluating critical medicines is a wholly transparent process conducted independently by the United States Defense Health Agency according to the processes and procedures outlined by Congress in the National Defense Authorization Act for Fiscal Year 2017. There are checks and balances throughout the process and the entire process itself is a matter of public record, which is detailed in numerous government documents including the “INFORMATION PAPER ON CLINICAL PRACTICE GUIDELINE PROCESS” which is excerpted below:
“The National Defense Authorization Act for Fiscal Year 2017 required the DoD to establish a program to develop, implement, update, and monitor clinical practice guidelines, which are evidence-based assessment and treatment recommendations to improve the consistency and quality of care delivered to military and veteran patient populations. Congress mandated that the Veterans Health Administration (VHA) and the DoD collaborate to develop Clinical Practice Guidelines (CPGs). The Defense Health Agency Clinical Quality Improvement Program is designated lead for the DoD.

DISCUSSION: The VHA/DOD Clinical Practice Guideline Program has an Evidenced-Based Practice Guideline Work Group (EBPWG) that considers topics for new CPGs and sets the schedule for fiscal year CPG development and updates. The EBPWG utilizes the VHA/DoD Guideline for Guidelines during the development of CPGs. After identifying a new CPG to develop, or a current CPG to update, clinical champions are selected to form a multidisciplinary subject matter expert WG with both VHA and DOD representation. The WG defines the target patient population and audiences and establishes key questions to guide the literature search and evidence review. For updates to existing guidelines, the WG critically reviews the CPG for alignment with current recommendations. Analysis of previous key questions and evidence informs new sets of key questions during the update process. For new CPG development the WG develops key questions from the ground up. The VHA and DOD also convene patient focus groups early in the process to better understand what is important to the patients that we serve. Key questions are developed using patient, intervention, comparison, outcome, and time (PICOT) statements. A systematic review of current literature is completed for each key question. The CPG WG reviews the evidence-based literature and makes recommendations for the guideline using the Grading of Recommendations, Assessment, Development and Evaluation system. The CPG is then drafted by the WG. There are 3 iterative drafts completed, with the third draft being sent externally for peer review. The final draft is sent to the EBPWG for approval. Once a CPG is approved, provider and patient clinical support tools (CSTs) are created. Approved CPGs and CSTs are available on DHA and VHA websites.”
The full document may be accessed at the link below: https://www.health.mil/Reference-Center/Publications/2024/01/26/AMSUS-CPG-Info-Paper


An independent panel of clinical toxicologists, physicians, and other domain specialists, none of whom were compensated by antivenom manufacturers, invested hundreds of hours in a systematic appraisal of every product on the market. Only antivenoms supported by rigorous clinical data and endorsed unanimously by this panel advanced. The review process adhered scrupulously to established scientific standards and was fully insulated from commercial influence; decisions were grounded solely in comparative safety-and-efficacy evidence. Products such as PANAF Premium likely were not considered as they have no published peer-reviewed clinical trials to support their use.
Mr. Juan Calvete of the Instituto de Biomedicina de Valencia, whose lab conducts antivenom tests for the WHO, was denied access to Polyserp-P when he tried to obtain samples in 2021. He was told by Polyserp Therapeutics that it was “only available to US military customers”.
Mr. Calvete is not a clinician, he does not treat patients. Concerningly, despite being the sole laboratory utilized by the World Health Organization for preclinical qualification of antivenoms, Mr. Calvete’s lab, Instituto de Biomedicina de Valencia, does not appear to be on any GLP certified list or hold other accreditation. GLP certification makes it compliant with relevant standards for a lab conducting such tests for a global health body, which is in the WHO’s own guidelines. For reference, GLP certification means a lab follows strict, internationally recognized rules to ensure its research is done properly, honestly, and can be trusted by regulators.
List of GLP certified facilities: https://www.aemps.gob.es/industria-farmaceutica/inspeccion-y-control/buenas-practicas-de-laboratorio/listadolab-bpl/?lang=en


Claim #6: He said some manufacturers might use broad claims about the effectiveness of its antivenom “as a marketing tool” but that “it is essential that any such claims be supported by data”. Currently only three antivenoms for sub-Saharan Africa carry a WHO recommendation. Ten more are undergoing assessment, of which Inoserp is one. But Polyserp has never been assessed by WHO. David Lalloo, a clinical researcher at the Liverpool School of Tropical Medicine, said the regulation of antivenoms “has just not been as tight as it should be” for patients around the world. He said any new version of an antivenom should, by any normal standards, be tested in proper clinical studies. Speaking generally, he added: “You cannot rely on previous studies, and particularly previous studies that relate to safety, to assure yourself of this being a safe and efficacious antivenom.” Polyserp Therapeutics and Inosan Biopharma did not respond to TBIJ’s questions about why they had used clinical trial data for one drug to promote the safety and effectiveness of another.

Rebuttal: This is already disproven above. The only true part is about regulation of antivenom. There needs to be a public expert opinion consensus by a working group on antivenom to prevent articles like this from potentially impacting public health through unverified information.
Inoserp has still to date not received a reason or paperwork by WHO on why they did not choose it.

False Claim #7: A US Army spokesperson told TBIJ that the army “does not conduct independent testing of medical products and does not have a third-party testing for snake antivenom”.


No cited Spokesperson, with no proof. If something already has strong data in humans, there is no reason to replicate it further and waste time, money and resources delaying a product with an urgent need for force health protection.

False Claim #8: Polyserp-P was recommended by the US Defence Health Agency’s Joint Trauma System (JTS) in 2020. The JTS told TBIJ: “The recommendations were based off subject matter experts who evaluated peer-reviewed medical literature and the manufacturer’s recommendations.” The literature it relied on does not mention Polyserp but did test Inoserp. The companies did not provide TBIJ with any evidence that Polyserp had been part of this research.The JTS told TBIJ that it “will always do our best with best evidence and [expert] input”, and added that it will review the relevant guidelines and update them as necessary. It remains unclear exactly how comparable Inoserp and Polyserp are. Certainly the prices that have been disclosed suggest two very different products. Calvete was initially quoted $6,300 for six vials of Polyserp-P in 2021, while a TBIJ reporter bought a single vial of Inoserp-P for $66 (£50) in Tanzania in 2024. The US Army did not respond to TBIJ’s requests for comment or to make samples available to test.

There isn’t a reason to send vials to a testing center on something that has already been proven. The Joint Trauma Service mission is to take the best care of soldiers and that is what it does, using peer-reviewed medical literature and subject matter expertise. If a product or technique is found to be newly superior or inferior, the JTS guidelines are able to be rapidly updated as living documents, faster than textbooks.
Call to action:
This incident shows the need for snake envenomation experts internationally to come together to aggregate the data and provide a transparent evidence based recommendation for existing products. This can ensure that new products are properly recommended and providers do not waste money acquiring subpar antivenom which could be unproven. With the obstacles around conducting RCT with antivenom, the next best step is to do meta-analysis of existing clinical data with expert opinion by clinicians who are actually on the ground treating people. While many of the snakebite experts volunteer their own time to provide services abroad to the point where they may be too busy to publish data of their ongoing experiences, it may be a time to prioritize data publication this year to enable data to prevail.
Currently, two places to get recommendations would be AZA and then Venom1, which is the national Antivenom bank.


This article also shows how important it is for providers at all levels to ensure they can properly recognize how to read literature (and the absence of it) to ensure that false news articles can be easily disproved and not negatively impact treatment of patients. Medical and non-medical personnel that cannot properly read literature are at risk of being swayed by weak assumptions or a lack of data.

We hope this results in a full and impartial investigation into the statements made, or if this is the official stance of The Guardian and TBIJ. Deletion of articles and a formal apology to the JTS and other parties would be preferable to maintain Journalist integrity. Moving forward we recommend Journalists evaluate research themselves and keep multiple clinicians available for consult to provide expert evaluation and opinion on subjects before spreading potentially harmful misinformation.

We have zero financial ties to disclose.