American anti-science activism is globalising
Antivaccine sentiments can be traced back centuries to objections against Jenner’s original smallpox vaccine in the 1800s in England or, even earlier, to variolation in the founding American colonies and elsewhere. Today, in many countries, objections against vaccinations – especially compulsory immunisations – remain. In 2010 The Vaccine Confidence Project was launched to document the unique national flavours of vaccine resistance across the globe.
Each country or subregion continues to have its own version of antivaccine sentiments, but a different, darker version of antivaccine activism has arisen in the United States. This US brand targets multiple aspects of biomedicine, including pharmaceuticals and pandemic denialism. It has also merged with climate denialism to create a formidable anti-science movement, which has begun to globalise across the Western Hemisphere and into Europe. It even threatens low- and middle-income countries in Africa and elsewhere.
Three pillars of antivaccination in America: Autism, politics and profit
In England, what began in the late 1990s with claims that vaccines cause autism, quickly gained a foothold in the US. My involvement in countering antivaccine claims stems from the dual nature of my professional and personal life: I’m a laboratory-based paediatrician scientist who develops new vaccines for neglected diseases and a dad of four adult kids, including Rachel, who has autism and intellectual disabilities. I have often been asked by professional societies and US government agencies to engage with antivaccine activists or debunk their false assertions. After multiple discussions with these activists, including Robert F Kennedy Jr, I wrote a book entitled Vaccines Did Not Cause Rachel’s Autism. As a result of it and other public activities, I have become a frequent target, but it has also given me a unique perspective. I’ve watched American antivaccine activism grow into a political and financial enterprise.
The political element arose in my state of Texas in the 2010s when political action committees began funding antivaccine activists. Invoking libertarian ideals and health freedom rhetoric, they encouraged parents to request exemptions for childhood immunisations required for school entry. Today at least 100,000 Texas schoolchildren do not receive their full complement of vaccines. Later, during the Covid-19 pandemic, health freedom expanded as politicians, in their zeal to push back against Covid vaccine mandates, began to falsely discredit the effectiveness and safety of vaccines. These attitudes were amplified on Fox News and conservative news podcasts and social media. My 2023 book, The Deadly Rise of Anti-science, estimates that 200,000 Americans needlessly died in 2021–2022 because they refused Covid vaccines. The deaths disproportionately occurred in Republican Party–majority states, including approximately 40,000 deaths in Texas. As the pandemic wound down, antivaccine sentiments again spilled over to childhood immunisations, causing a large 2025 measles epidemic that has extended from Texas to three additional states. It has resulted in 100 hospitalisations and two deaths of unvaccinated schoolchildren.
The financial aspect stems from the wellness and influencer movement seeking to peddle generic medicines and supplements, which they could buy in bulk and repackage together with expensive telehealth visits. Their drugs of choice: low-cost antiparasitics such as ivermectin, hydroxychloroquine and fenbendazole. This has become a lucrative business empire.
An anti-science ecosystem
Now with Robert Kennedy as secretary of the US Department of Health and Human Services, the antivaccine rhetoric has acquired an unprecedented platform, as he attempts to resurrect vaccine-autism links and discredit the measles-mumps-rubella vaccine or mRNA vaccines for Covid and future pandemic threats. In his first few months, Mr Kennedy has consistently downplayed the MMR vaccine in favour of vitamins or (in a nod to the wellness industry) a cocktail of medicines – vitamin A, budesonide and clarithromycin. Many activists further claim pandemics are hoaxes or planned for personal gain by scientists or public health officials. The term ‘plandemic’ has entered the lexicon.
Academic health centres and research universities are also under threat. The Trump administration has proposed a nearly 40% cut to the US National Institutes of Health budget, with some universities such as Harvard, Columbia and the University of California system threatened with additional sanctions. In my latest book, with Michael Mann, Science Under Siege, we compare the coordinated attacks against both biomedicine and climate science.
Will this unique brand of American anti-science, linked to extremist politics and wellness influencer products, globalise? American anti-science has already gone beyond US borders into Canada where measles outbreaks are also underway. In addition, the US government has indicated its intention to pull critical financial support for science-driven global health organisations, including the World Health Organizationand Gavi, the Vaccine Alliance. But documenting the spread of US antivaccine–anti-science activism to LMICs in Africa, Asia and Latin America is not straightforward or easy to document, given that it mainly occurs through local media, WhatsApp and other personal device messaging. Reports on American antivaccine leaders pop up often on local news sites in LMICs, as do antivaccine films made in the US. It is not unusual to learn of LMIC government leaders repeating antivaccine and anti-science rhetoric from the US.
In 2023, the WHO sounded an alarm regarding the decline in MMR vaccination rates and the return of measles and other childhood illnesses. The concern is that this reflects the globalisation of what accelerated out of Texas a decade ago. For years, I would visit Latin American countries to address their medical societies. I would begin by congratulating their physician members on holding the line and preventing the contamination of US antivaccine activism south of the border. This is no longer the case. I am concerned that increasingly vaccination rates will decline in LMICs across the world. Our global vaccine ecosystem is fragile.
