The US Department of Health and Human Services is now run by conspiracy theorists who believe that the American public health system is hiding key data on vaccine safety and who spend their days spreading health misinformation. Secretary Robert F. Kennedy Jr. regularly promotes the false claim that childhood vaccines cause autism.

Kirk Milhoan, his appointed chairperson of a committee that makes recommendations about the vaccine schedule, has falsely claimed that 80 percent of women who receive a COVID-19 vaccine in their first trimester will miscarry and that childhood vaccines are causing an increase in cardiovascular disease in young adults (Zadrozny 2025b; Stobbe 2025). John Knox, the new acting director of the Administration for Strategic Preparedness and Response—the organization which shapes the government response to public health crises—described the COVID vaccination campaign as a “genocide,” and falsely claimed that COVID vaccines contained HIV and that mpox was an autoimmune response to them (Zadrozny 2025a). The super spreaders of health misinformation are no longer fringe figures. They now control public health in the United States.

Health misinformation is a complex problem with no simple solutions. It’s both a symptom of broader societal issues (e.g., attacks on science, lower societal trust) and a cause of misbeliefs, confusion about health topics, and reduced vaccine uptake. Yet, interventions are possible.

Misinformation spread by people in power is difficult to counter and doing so is especially challenging at a time when social media companies appear to be abandoning the effort. But by targeting the supply, demand, distribution, and uptake of misinformation, it is possible to improve the information environment and help people make informed health decisions.

What is health misinformation?

Misinformation is difficult to define, and while experts agree on many of its key factors, disagreement persists on the boundaries of the term (Altay et al. 2023). As a psychologist who researches misinformation, my favorite definition is an adaptation of the definition of science misinformation proposed by a recent National Academies of Sciences, Engineering and Medicine consensus study (Viswanath, Taylor, and Rhodes 2024). Misinformation about health is information that asserts or implies claims that are inconsistent with the weight of accepted scientific evidence at the time.

As the definition makes clear, misinformation encompasses more than just false statements. True information that strongly implies a false conclusion—like a widely shared 2021 Chicago Tribune headline during the COVID pandemic, “A ‘Healthy’ Doctor Died Two Weeks After Getting A Covid−19 Vaccine; CDC Is Investigating Why”—can still be classified as misinformation. It was technically true, but strongly implied that the vaccine was a plausible cause for the doctor’s death.

The widespread availability of this type of misleading but not explicitly false content on Facebook was estimated to have reduced COVID vaccination intentions by 2.3 percentage points per US Facebook user, according to one study (Allen, Watts, and Rand 2024).

Moreover, the status of a statement can change as scientific evidence accumulates. This instability is part of why defining and combatting health misinformation is difficult. Our understanding of human health is still evolving, and with it our classification of claims as true or false.

The misinformation behavior connection

Misinformation exists within a complex web of forces that affect health behaviors. Isolating the exact effects of health misinformation on behavior is very difficult. For example, someone may decide not to get a yearly flu shot for more than one reason—be it the inconvenience of making an appointment, the hassles of travel, or a fear of needles.

While exposure to the false narrative that flu shots are ineffective may have played a role in that decision, it is difficult to quantify the exact effects of health misinformation on people’s health decisions. Misinformation researcher Claire Wardle likens the effects of misinformation exposure to the effect of drops of water on a rock: The impact of any individual drop is imperceptible, but over time the shape of the rock is dramatically changed (Wardle 2023).

Overall, health misinformation has a larger effect on shaping beliefs than it does on shaping behaviors (van der Linden et al. 2023). In other words, misinformation is more likely to make you believe something false like “The aluminum used in childhood vaccines is dangerous” than it is to make you not follow your pediatrician’s vaccine recommendations. That said, health misinformation does have measurable impacts on people’s actions.

For example, one study reported that in early 2019 the amount of vaccine-related misinformation shared by Twitter-users in a given US county forecasted changes in vaccine hesitancy in that same region 2-6 days later (Pierri et al. 2022). Another study showed that patients who choose to treat their cancers with alternative medicine rather than conventional treatments such as chemotherapy and surgery—a decision often based on health misinformation—were more likely to die within the next five years (Johnson et al. 2018).

Studies have also tied widespread disease outbreaks to health misinformation.

In 2017, the Somali immigrant community in Minnesota was at the center of a large measles outbreak. The community was concerned about the number of their children who were being diagnosed with autism, a rare diagnosis in Somalia. According to journalists and scholars, anti-vaccine activists then exploited local worries and spread misinformation about vaccine safety, including the false claim that the measles, mumps, and rubella (MMR) vaccine causes autism (DiResta 2018; Molteni 2017). Immunization rates for young children in the community dropped from over 90 percent in 2008 to 36 percent in 2014 (Hall et al. 2017).

Effective interventions

Health misinformation is a whole-of-society problem with no quick fixes, but that does not mean that we are doomed to live in a world without easy access to accurate health information. In a recent study on understanding science misinformation, my colleagues and I identified four points at which it might be possible to intervene and disrupt misinformation: supply, demand, distribution, and uptake (Viswanath, Taylor, and Rhodes 2024).

Supply. The aim of supply interventions is to reduce the amount of misinformation circulating in society or increase the availability of accurate information. Thus, interventions aimed at supporting high-quality information (such as funding health journalism) and interventions aimed at reducing low-quality information (such as deplatforming accounts that repeatedly share misinformation) count as supply-based interventions. Common interventions include moderation policies, demonetization, and changes in algorithmic prioritization.

Demand. People are not simply passive consumers of health misinformation; they often seek it out either to confirm their preexisting beliefs or to answer pressing questions. Demand-based interventions aim to reduce this demand for misinformation by addressing people’s information needs, increasing trust in accurate information, and increasing people’s ability to notice and avoid misinformation through media literacy training.

Demand interventions include social listening tools that focus on what people are searching for or posting online and what they’re hearing about public health topics. For example, the website “infodemiology.com” hosts dashboards that follow public conversations about vaccines in the United States from social media, news sites, video sites, and other sources. Organizations such as medical societies, patient advocacy groups, and local health departments can then use these resources to create content that addresses common patient concerns and questions (and platforms can prioritize that content) making it more likely that people will easily find high-quality information.

Distribution. Another strategy to counter misinformation involves slowing or disrupting its spread. Distribution interventions can involve platforms controlling their algorithmic amplification of content and reducing promotion of posts that have been classified as misinformation. Algorithms could also be tweaked to be wary of rapidly spreading posts that haven’t yet been reviewed by content moderators (Viswanath, Taylor, and Rhodes 2024).

Distribution interventions can also be aimed at influencing individuals’ decisions to share information with others. People often decide to share misinformation because in the moment they are not paying attention to signals of accuracy and information quality. This could be done by accuracy nudges (which remind people to consider the accuracy of what they are reading) and by friction interventions (which encourage people to reconsider their initial responses). Accuracy nudges and friction interventions can be effective in reducing shares of misinformation on online platforms (Pennycook and Rand 2022; Pillai and Fazio 2023).

Uptake. Finally, uptake interventions aim to prevent belief in misinformation after exposure. These interventions can occur before, during, or after exposure to the false claim. Media literacy interventions, pre-bunking, and inoculation all aim to teach people about the rhetorical techniques used by disinformers and how to recognize common misinformation topics and narratives prior to exposure. For example, reading an article refuting common anti-vaccine conspiracy theories protected people from believing later vaccine misinformation (Jolley and Douglas 2017). Content labels which include information about the reliability of the source, or factchecks that provide additional information, can help people judge accuracy. Debunks presented after exposure to misinformation can also be effective when they come from trusted sources, provide detailed information (more than just a true or false label), and explain why the information is false (Viswanath, Taylor, and Rhodes 2024). Doctors and other health professionals can provide personalized debunking for their patients by listening with empathy to patients’ questions and concerns, and providing information about current scientific consensus.  While deeply entrenched misbeliefs can be difficult to correct, many patients are simply curious or unsure, and an empathetic conversation can be very helpful.

Challenges for implementation

Researchers and practitioners hoping to employ misinformation interventions face multiple challenges. Most supply and distribution interventions require the cooperation of social media platforms and other information distributors for their implementation and testing. Researchers need data, for example, but companies have blocked access.

In addition, many companies have done extensive internal testing of the effectiveness of their policies, but rarely share the results with the public or outside researchers (Samuel 2025). While recent policy changes like the Digital Services Act in the European Union may increase future scrutiny and auditing of technology companies and their moderation decisions, right now there seems to be little appetite for stricter regulation—especially in the United States.

In fact, as the political winds shifted from the Biden to the Trump administration, social media companies began to abandon the interventions they once embraced. While political pressure used to encourage platforms to take action against misinformation, the current pressure is instead to loosen regulations due to perceived anti-conservative bias.

In January 2025, Meta eliminated their partnerships with US-based fact-checkers. Started in 2019, these partnerships had allowed Meta to avoid making difficult calls about misinformation themselves, instead financially supporting fact-checking organizations whose judgments were used to reduce the reach of flagged posts and add context and additional information.

Similarly, despite previously using fact-checking panels in both their search results and on YouTube, Google trashed fact-checkers in September 2025. In fact, it even agreed to reinstate the accounts of multiple creators who had previously been banned for repeatedly spreading COVID misinformation. When Twitter (now X) changed hands, new owner Elon Musk removed many of the platforms’ policies prohibiting various types of misinformation. In addition, CrowdTangle—a  transparency tool that allowed researchers and journalists to see what posts were trending on Facebook and Instagram—was discontinued by Meta in August 2024. As mentioned above, this type of social listening is vital for combatting health misinformation.

And our health misinformation problems may be set to deepen.

AI-generated health misinformation is quickly becoming a new frontier for grifters, and platforms are doing little to combat the problem. A recent investigation found that over two dozen social media accounts featuring AI-generated videos of doctors promoting various supplements and e-books. Together the accounts had over 8.5 million followers or subscribers; their videos regularly receive tens of thousands of engagements (Silverman 2026). Platforms are also failing to correctly label AI-generated content, even when the content is created using their own AI tools (Mantzarlis and Dutta 2025).

The real problem

Overall, health misinformation is most harmful when it is being spread by individuals with power and through well-resourced campaigns (Viswanath, Taylor, and Rhodes 2024). In other words, exactly what is happening within the Trump administration now.

There are several historical examples of this phenomenon in action. In the 1980s, the Soviet Union launched a disinformation campaign that amplified rumors that the US government created the HIV virus as a bioweapon (Selvage 2019). This false narrative, along with other AIDS misinformation, led South African officials to delay the implementation of an antiretroviral treatment program and led to an estimated 330,000 additional deaths in the country (Chigwedere et al. 2008). Elon Musk’s belief in misinformation about the US Agency for International Development (USAID) led him, newly empowered within the Trump administration, to dismantle the agency, leading directly to an estimated 600,000 deaths around the world in the first nine months (Gawande 2025; Moynihan and Zuppke 2025).

Yet, many of the most well-studied misinformation interventions focus on altering the behavior of the general public rather than those with the most influence. Interventions such as media literacy, accuracy nudges, pre-bunking, and fact-checking are all useful in helping people navigate our current media landscape and make more informed health decisions. They do little, however, to curb the influence and impact of public health leaders who do not believe in public health.

More broadly, it is essential for society to value truth and accuracy, and to punish purposeful lying and deception. Americans do not want to be misled—75 percent of US adults are very or extremely concerned that the spread of misinformation poses a direct threat to the United States (Associated Press 2023). However, disinformers will continue to spread health misinformation (for profit, power, or fame) until there are societal consequences for their lies.

A famous study conducted just prior to the 2012 US election sent letters to randomly selected state legislators across nine states (Nyhan and Reifler 2015). These letters let the legislators know that political fact-checkers were working in their state, described the potential electoral and reputational consequences of having a negative rating from the fact-checking organization, and included some sample fact-checks about other politicians. The researchers found that legislators who received the letters made fewer inaccurate statements during the electoral season.

President Donald Trump’s elevation of figures like Kennedy, among many other actions, raises doubts about whether politicians and other public figures are still concerned about what will happen to their reputation if they are accused of making false statements. In fact, many figures in Trump’s orbit treat being corrected as a badge of honor; they seem to interpret it as a signal that they are persecuted “truth-tellers” who are fighting for the common man against out-of-touch scientists, journalists, and public health officials. After all, we live in an era when a former aide to the president, confronted about false White House statements in 2017, famously pointed to there being “alternative facts” Given that health misinformation is most damaging when it is believed and spread by those in power, we will continue to see its harmful effects until there are reputational harms for spreading lies.