Three people, including two children, died of measles in the United States in 2025. Their deaths were preventable. There were 2,267 confirmed measles cases in the US last year – more than seven times the 285 cases in 2024, and the highest number in more than 30 years. All these cases were preventable, too. So, why weren’t they? For two decades, Robert F. Kennedy Jr., who was confirmed as the Secretary of the US Department of Health and Human Services last February, has promoted baseless theories linking vaccines with autism. He has claimed that vaccines have “poisoned an entire generation of American children,” and his statements are likely to have contributed to declining vaccination rates in the US. This has led to a sharp increase in the incidence of measles.
Since taking office, Kennedy has fired experienced scientists from a key vaccine advisory committee and replaced them with sceptics. He has also withdrawn funding for developing mRNA vaccines –the method of developing new vaccines that enabled the rapid production of highly effective vaccines against COVID-19, probably saving several million lives. Kennedy suggested taking vitamin A as an alternative to measles vaccination, after which some Texas parents gave their children such high doses that the children showed symptoms of toxicity. The turn away from the usual standards of science in public health is not only an American problem. In Slovakia, Prime Minister Robert Fico appointed Peter Kotlár, an orthopaedic surgeon and anti-vaccine activist, to investigate the country’s pandemic response. Kotlár’s October 2024 report described COVID-19 as “an act of bioterrorism” designed to “test the naivete of the global population to follow orders subliminally.” The report also claimed, without evidence, that mRNA vaccines alter human DNA, and recommended that they be banned.
In a free society, individuals may express their unfounded opinions about vaccines, knowledgeable scientists can rebut them, and public-health officials should examine the evidence and act accordingly. In rare cases, views opposed to a scientific consensus will turn out to be true and become a new orthodoxy.
Public-health officials occupy roles of special responsibility because they shape policies affecting millions. Vaccines are among the most extensively tested medical interventions in history. Yet vaccine sceptics like Kennedy demand ever-more studies, while accepting far lower evidentiary standards for their own claims – anecdotes, cherry-picked data, and conspiracy theories about pharmaceutical companies.
When vaccination coverage drops below critical thresholds, “herd immunity” –the protection vulnerable populations receive from high vaccination rates in the general population –is lost, and preventable diseases return. We know this from historical precedent and from contemporary examples like Romania and now Canada, where measles had been considered eliminated. Under communism in Romania, childhood vaccination was compulsory, and measles was effectively eliminated. While the fall of the Ceaușescu dictatorship brought welcome freedoms, and EU membership improved living standards, one consequence was that some vaccines became voluntary. By 2023, the measles vaccination rate in Romania had fallen to 62%, down from 95% when the vaccine was introduced, and in 2024, the country had more than 30,000 measles cases, including 23 deaths.
Some officials say they are simply respecting individual liberty. But liberty for competent adults to make their own choices does not extend to decisions that harm others. Refusing childhood vaccination does exactly that. Children attending kindergarten or elementary school should be vaccinated, not only because it will protect them, and they are too young to make their own choices, but also because refusing vaccination increases the risk to others who are too young for vaccination, as well as to immune-compromised individuals who cannot be vaccinated and to the broader community when herd immunity breaks down.
Kennedy presents himself as fighting pharmaceutical company power, pointing to genuine scandals like Purdue Pharma’s promotion of OxyContin. But well-documented cases of corporate malfeasance do not justify rejecting an entire category of medical intervention supported by scientific evidence for safety and efficacy that comes from independent researchers, public-health agencies worldwide, and decades of population-level data. The suggestion that this global scientific consensus is some vast conspiracy is wildly implausible.
When government officials act on unfounded beliefs about vaccine risks, people die, as the unvaccinated Texas children who contracted measles died. Those who wield power over health policy bear responsibility for these outcomes. Epistemic recklessness – persisting in beliefs contradicted by overwhelming evidence when many lives depend on getting it right – is a basic ethical failure.
Of course, scientific understanding is never perfect or final. Genuine questions about vaccine safety merit serious investigation – which is why vaccine-safety monitoring systems exist, and why rare adverse events are carefully studied. But there is a wide gap between good faith inquiry and ideological resistance to overwhelming evidence. Disregard for scientific evidence by opponents of vaccination is now producing exactly the harms experts predicted: disease outbreaks, preventable deaths, and the unravelling of progress in public health that took decades to achieve. This must stop now, before the consequences become truly catastrophic.
Governments should appoint officials with relevant scientific expertise who respect evidence. Public-health agencies should operate according to scientific consensus, not political ideology. And when officials demonstrate sustained commitment to views contradicted by evidence, they should be removed from positions where they can translate those views into policies with deadly consequences.
The writer is Professor in Medical Ethics at the Centre for Biomedical Ethics, National University of Singapore.
