Science Facts & Fallacies

Never uncertain but frequently wrong, Kennedy had to ignore extensive scientific evidence to make such declarations. mRNA vaccines have been rigorously tested, with clinical trials involving tens of thousands of people showing over 90% efficacy in preventing severe COVID-19 outcomes. Studies estimate the shots have saved millions of lives globally over the last five years, reducing hospitalizations and deaths even as variants emerged.

While mRNA vaccines are best known for saving lives during the pandemic, they hold truly transformative potential for addressing chronic diseases, Kennedy’s pet project since taking the helm at HHS. In cancer therapy, for instance, mRNA can be tailored to encode neoantigens—unique proteins found on an individual’s tumor cells. By sequencing a patient’s tumor, scientists identify these neoantigens and design vaccines that prompt the immune system to recognize and attack cancer cells while sparing healthy tissue. The flexibility of mRNA technology allows rapid vaccine development customized to each patient’s unique case, revolutionizing oncology by offering targeted, effective, and adaptable treatments.

Defunding mRNA research stifles innovation in a platform with proven potential beyond COVID-19. The technology’s rapid adaptability could be critical for preventing or mitigating future pandemics, yet Kennedy risks undermining that progress by relying on discredited studies and misrepresenting data, undermining trust in vaccines along the way. By prioritizing supposedly “safer” platforms, he jeopardizes scientific innovation, leaving the U.S. vulnerable to future health crises. Simply put, it’s a decision that prioritizes ideology over evidence.

Join Dr. Liza Lockwood and Cam English on this episode of Facts and Fallacies as they discuss the consequences of halting mRNA vaccine progress.

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Some experts say the answer lies in legalizing and regulating all drugs, treating them much like pharmaceutical products that can be dispensed by licensed physicians or sold over the counter by reputable retailers. This approach, the argument goes, would significantly reduce the risk of users consuming contaminated (and thus more harmful) drugs and encourage them to seek medical care when necessary. Ultimately, the goal with this policy is to make drug use safer instead of reducing or eliminating it.

While this strategy probably has some merit, it also carries risks that shouldn’t be overlooked. For example, experts on both sides of the debate recognize that legalization will increase drug use. “There’s no question about it,” says Bertha Madras, a professor of psychobiology at Harvard Medical School. And that surge in use will very likely fuel an increase in drug abuse, which most people recognize as a serious threat to public health. A related cost comes in the form of increased public investment in health care related to drug use—an expense covered by all taxpayers, not just individuals who decide to use.

To help us make sense of these competing claims, emergency medicine physician Liza Lockwood fields some of the most common questions about drug use and regulation, breaking down the risks and benefits of legalization in detail.

Join Dr. Liza Dunn and Cam English on this episode of Facts and Fallacies as they discuss the science and ethics of drug legalization

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

The conversation was further complicated by updated vaccine guidance issued by the FDA and CDC in May, which recommended that only high-risk groups receive annual COVID boosters, revising the previous guidance that all Americans over the age of 6 months receive the shot each year. While the new recommendation makes a certain degree of sense, some physicians have noted that it introduces new questions for patients, doctors, and pharmacists that federal officials have yet to answer. Vaccine expert Dr. Paul Offit outlined several such questions recently, including this one:

“I am a pharmacist who gives dozens of Covid-19 vaccines every day. Am I supposed to determine whether someone is in a high-risk group before I give the vaccine? And how could I possibly know whether people are telling the truth. Will I get into trouble if I give a Covid vaccine to a healthy young person?”

To help cut through the confusion, emergency medicine physician Dr. Liza Lockwood answers the most common questions about COVID-19 vaccines: how do they work, and why do they only protect against severe disease and death—as opposed to preventing infection and transmission? Are the new guidelines from FDA/CDC justifiable?

Join Dr. Liza Dunn and Cam English on this episode of Facts and Fallacies as they discuss they break down the latest science around COVID vaccination:

Dr. Liza Lockwood is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Many researchers argue that these severe measures were well-intended attempts to reduce the spread of SARS-CoV-2, but public health officials did a poor job of justifying their implementation. For instance, mass protesting and rioting in the summer of 2020 — before COVID vaccines had been authorized — were endorsed by “dozens of public health and disease experts,” according to NPR, while most other activities were prohibited in the name of minimizing viral transmission. “[A]s public health advocates, we do not condemn these gatherings as risky for COVID-19 transmission,” an open letter signed by these experts declared. “We support them as vital to the national public health …”

Adding fuel to the outrage fire, scientists who criticized these inconsistent infection-control measures were censored by social media platforms under pressure from the federal government. This environment helped birth the MAHA movement, which with RFK, Jr. at the helm has accelerated its broader opposition to conventional medicine—most notably well-studied pediatric vaccines that have a long track record of preventing infectious disease and saving lives.

The history of the COVID-19 pandemic is a painful narrative with a lot of lessons to teach, if we’re willing to learn them. As health scientist Jess Steier recently explained, “It’s a story about what happens when public health policy collides with deeply held American values about autonomy and skepticism of authority—and how even well-intentioned overreach can have consequences that last far longer than the crisis that justified it.”

The ultimate solution to the excesses of the MAHA movement is a stronger bond between scientists and the general public. But rebuilding that relationship requires transparent communication, acknowledging uncertainty, and fostering open debate rather than dogmatic mandates. Above all else, the fallout from COVID policies underscores the need for humility in public health to prevent further erosion of credibility and the rise of reactionary movements like MAHA.

Join Dr. Liza Dunn and Cam English on this episode of Facts and Fallacies as they discuss the lessons scientists are learning from the pandemic:

Dr. Liza Dunn is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Biltekoff parallels 19th-century dietary reformers—detailed in Laura Shapiro’s Perfection Salad—who tried to use nutrition science for social engineering, with Alice Waters’s “Delicious Revolution” in the San Francisco Bay Area, which prioritized sensory pleasure and tradition over standardization. Both movements sought cultural transformation through diet, but with contrasting ideologies. The similarities between these movements and the factions in our current food safety debates are striking.

One of the most important lessons that comes out of Biltekoff’s analysis relates to definitions: the public often views processed food as unnatural and additive-heavy, while industry defines it broadly (e.g., yogurt, pasta, and Cheetos all qualify). Simultaneously, however, consumers demand flavorful, nutritious food that will keep in their refrigerators and pantries until they’re ready to eat it—qualities usually made possible by food processing. In other words, the food industry is correctly responding to their customers’ buying habits, yet those same people have been convinced that the products they willingly purchase are made by unethical companies and causing chronic disease.

This schizophrenic dynamic intensified with the onslaught of anti-food industry documentaries like Super Size Me and Food, Inc., which cleverly framed food safety issues as symptoms of broader cultural problems, like corporate greed. Industry responses to these films were typically fact-focused rebuttals that overlooked the cultural concerns actually driving popular opposition to the modern food system, an approach Biltekoff calls “food scientism.”

Ultimately, Biltekoff advocates combining cultural and scientific expertise to address food challenges, acknowledging complexities in feeding the world sustainably.

Join Dr. Liza Dunn and Cam English on this episode of Facts and Fallacies as they discuss the messy politics of food safety and science communication.

Dr. Liza Dunn is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

The ongoing measles outbreak in the U.S. has fueled intense speculation about how politics influences vaccine hesitancy. With over 1,200 confirmed cases reported across 37 jurisdictions by mid-2025, the outbreak underscores the reemergence of a disease once eliminated in the U.S. in 2000, largely due to declining vaccination rates. According to recent data from a Kaiser Family Foundation (KFF) Tracking Poll, a significant portion of Americans, particularly Republicans, are encountering and accepting misinformation about the measles, mumps, and rubella (MMR) vaccine. The poll indicates that 20 percent of Republicans and 21 percent of independents believe or lean toward the notion that the MMR vaccine is more dangerous than measles itself, compared to just 11 percent of Democrats. This dichotomy is also evidenced by 35 percent of Republicans and 26 percent of independents accepting the false link between the shot and autism, against only 10 percent of Democrats.

While these numbers suggest that partisanship is a useful metric for measuring vaccine hesitancy, zooming out and considering a broader context paints a different picture. The same polling data shows that, despite widespread exposure to false claims—such as the idea that vitamin A can prevent measles—83 percent of adults and 78 percent of parents remain confident in the MMR vaccine’s safety.

Moreover, less than five percent of adults say it’s “definitely true” that the MMR vaccine has been proven to cause autism, or that getting the measles vaccine is more dangerous than a measles infection. Finally, “much larger shares [of the public] say those same claims are ‘definitely false,'” KFF reported. Most Americans, whatever their political affiliation, are not anti-vaccine, with about half falling in the “malleable middle,” meaning they can be convinced to immunize their children.

This points to a potential but serious issue with politicized vaccine messaging. Research shows that amplifying vaccine hesitancy tends to encourage more of it; if the media reports that vaccine skepticism is commonplace, Americans are more likely to adopt that perspective. “The most powerful way to convince students to get vaccinated for influenza was telling them that a large proportion of fellow students had also opted for vaccination,” one analysis of vaccine-promotion strategies concluded. “There is considerable evidence that letting people know what other people do is one of the most effective ways of increasing that behavior,” the authors added.

In other words, since large majorities of the public and parents are “very” or “somewhat confident” that the MMR vaccine is safe, those facts should be stressed to the minority who are scared or skeptical of vaccines. Bottom line: politicizing vaccine hesitancy is a PR faux pas. Public health experts, physicians, and journalists should be encouraging all Americans to vaccinate their kids.

Join Dr. Liza Dunn and Cam English on this episode of Facts and Fallacies as they discuss the link between political partisanship and vaccine hesitancy.

Dr. Liza Dunn is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Many journalists are fair-weather fans of science, adopting an evidence-based stance only when it aligns with their political leanings. For instance, every major media outlet has rightly chastised Health and Human Services Secretary RFK, Jr. for his anti-vaccine stance, yet it was these same news organizations that amplified his movement for decades, putting clicks and ad revenue ahead of their obligation to inform readers.

This selective enthusiasm from the press distorts the public’s understanding of science, giving them tacit permission to reject evidence that runs afoul of their ideological commitments—a troubling phenomenon we see at work in the Make American Health Again (MAHA) campaign.

Second, science journalists often lack deep knowledge of the fields they cover. Accurately reporting on complex topics like genetics or epidemiology requires years of study to develop a baseline understanding of those fields, yet many reporters rely on press releases and fail to engage experts who can correct their misunderstandings, leading to oversimplified or inaccurate stories that misrepresent nuanced findings. As a result, the public is forced to interpret sensational headlines without context.

Perhaps most importantly, science journalists rarely acknowledge their mistakes, further damaging trust. When errors or misinterpretations are exposed – for instance, flawed reporting about COVID-19 – corrections are seldom issued. Whether it’s the result of pride, ignorance, or ideological bias, this refusal to admit fault reinforces skepticism toward science itself, as audiences conflate journalistic failures with scientific ones.

To fix this mess, journalists need to embrace the rigorous standards they pay lip service to: prioritize impartiality where possible, cultivate a deeper understanding of science, and seek accountability. The solutions are obvious. The real question is, will reporters even acknowledge they have a problem?

Join Dr. Liza Dunn and Cam English on this episode of Facts and Fallacies as they discuss the issues plaguing science journalism and how to solve them.

Dr. Liza Dunn is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

Over the last decade, a growing chorus of scientists has declared that biological sex is not binary. Properly assessing human diversity requires us to apply a broader definition of this word, the argument goes. “The term ‘biological sex’ has been used to sort all people into one of two groups,” a May open letter from hundreds of scientists to the UK’s Minister for Women and Equalities asserted. “However, a strict, binary categorization is an over-simplification.”

The letter – signed by more than 350 academics, clinicians, and activists – is carefully argued, meticulously footnoted—and fundamentally mistaken about a basic biological reality. “Such statements … are most astounding as they ignore or even reject the well-established biological concept of sex and, thus, they ultimately deny fundamental principles of biology,” a team of evolutionary biologists wrote in 2023, responding to similar statements published by several academic journals.

Evolution, a scientific concept as well established as gravity, excludes the idea of a sex spectrum by confirming that biological sex is a binary trait in humans and most mammals. Evolution has shaped organisms to maximize reproductive success, resulting in two distinct sexes—male and female—defined by their roles in producing sperm or eggs. Males produce small, mobile gametes (sperm), while females produce larger, resource-heavy gametes (eggs). This binary system, driven by the need for genetic recombination, is a fundamental mechanism of sexual reproduction, observable across species. “With a few exceptions, all sexually reproducing organisms generate exactly two types of gametes that are distinguished by their difference in size,” the 2023 essay  added.

Intersex conditions, which are rare (approximately 0.018% of the population) and often involve ambiguous genitalia or chromosomal variations, are medical anomalies, not evidence of new sexes or a spectrum. They do not alter the binary framework, as they typically derive from disruptions in male or female developmental pathways.

The notion of a “sex spectrum” conflates sex with gender identity or secondary sexual characteristics, ignoring the objective, gamete-based definition of sex. Evolutionary biology shows no mechanism for a continuum of sexes. Scientists who endorse the sex spectrum often prioritize social or ideological considerations over empirical evidence, denying the binary reality established by evolutionary pressures.

By rejecting these basic facts, sex-spectrum advocates undermine the rigor of biology, misrepresenting a field that relies on testable, reproducible evidence. They also fuel mistrust of science, making it even harder for experts to convince the public that their scientific and medical claims are grounded in solid evidence.

Join Dr. Liza Dunn and Cam English on this episode of Facts and Fallacies as they discuss the science of reproduction and raise some critical questions about the sex spectrum.

Dr. Liza Dunn is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Follow him on X @camjenglish

With a growing number of US states legalizing marijuana use, scientists and policymakers are once again engaged in a pitched battle over the risks and benefits of THC, the primary psychoactive component of marijuana. Proponents argue that legalization offers important benefits, citing evidence that marijuana may help treat a variety of medical conditions ranging from chronic pain to epilepsy and nausea, while generating substantial revenue–as much as $60 billion according to one estimate–for state and local governments. Legalization, advocates add, also protects public health as safer, regulated sources of marijuana come online to replace black-market alternatives.

But the situation appears to be more complicated than many legalization proponents let on. Critics cite research showing that lax marijuana laws tend to significantly increase use, amplifying the drug’s harmful side effects. For example, some studies show that legalization boosts emergency room visits for psychosis and cannabis hyperemesis syndrome (CHS)—an unpleasant condition characterized by simultaneous screaming and vomiting, often called scromiting. “With the widespread use, increased potency and legalization of marijuana in multiple states in the U.S., CHS may be becoming increasingly common,” the Cleveland Clinic warns.

And while the direction of the association is uncertain (does THC cause mental health disorders or do people with those disorders gravitate toward marijuana) it’s clear the drug is linked to conditions like schizophrenia.

Although drug prohibition is usually the purview of social conservatives, former New York Times reporter Alex Berenson has emerged as perhaps the most forceful opponent of legalization in recent years, arguing in his 2020 book “Tell Your Children: The Truth About Marijuana, Mental Illness, and Violence” that cannabis is far more harmful than the public has been told.

To make sense of these competing claims, Cam and Liza speak with Reason Foundation health care policy analyst Jacob James Rich about his critique of Berenson’s work and the broader effects of drug legalization. Is it time to fully legalize marijuana, or has the public been sold a bill of goods by the drug’s defenders? Let’s take a look.

Jacob James Rich is a policy analyst at Reason Foundation, specializing in prescription and illegal drug regulations. He holds master’s degrees in mathematics and economics and is currently a Ph.D. student at Case Western Reserve School of Medicine. Follow him on X @jacobjamesrich.

Dr. Liza Dunn is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Visit his website and follow him on X @camjenglish

There’s a growing panic over per- and polyfluoroalkyl substances (PFAS), most recently targeting fluoropolymers used in medical devices. The issue is presented to the public as a grave health threat: “forever chemicals” lurking in medical devices and other seemingly innocuous products that could cause terrible harm. In reality, it’s another campaign by the “activist-tort-lawyer-media complex” that threatens lifesaving technology through fear-driven narratives rather than scientific evidence, says GLP founder Jon Entine. Rather than a danger to public health, fluoropolymers, a subset of PFAS, are critical tools that have saved millions of lives due to their unique properties such as chemical stability and durability.

These materials have proved their safety and efficacy in spades. Yet, activists and tort lawyers, often backed by ideological and gullible media outlets, have demonized all PFAS, leading to calls for blanket bans, as seen in the EU where countries like Germany and Sweden push for restrictions.

Like so many chemical risks, PFAS harms are wildly exaggerated, with recent research showing that low-level exposure primarily comes from water, not consumer products like medical devices. Entine chastises the Environmental Working Group (EWG) for needlessly scaring the public, a tactic echoed by the EPA’s 2019 action plan labeling all PFAS as hazardous despite the fact that this class of chemicals includes over 4,000 compounds varying widely in toxicity. This one-size-fits-all approach ignores toxicology’s bedrock principle of “the dose makes the poison.” In fact, fluoropolymers are not bioavailable due to their high molecular weight, making them perfectly safe when used as intended.

Bottom line: banning fluoropolymers could disrupt medical supply chains and hinder innovation, putting millions of lives in harm’s way. The smarter approach? Perform individual chemical risk assessments to balance safety and utility and reject simplistic activist-driven narratives that disregard sound science.

Podcast:

Join hosts Dr. Liza Dunn Cameron English and Jon Entine on episode 318 of Science Facts and Fallacies as they discuss:

Jon Entine is the founder and executive director of the Genetic Literacy Project. Follow him on X @jonentine.

Dr. Liza Dunn is a medical toxicologist and the medical affairs lead at Bayer Crop Science. Follow her on X @DrLizaMD

Cameron J. English is the director of bio-sciences at the American Council on Science and Health. Visit his website and follow him on X @camjenglish