WHO Immunization Director's September 2025 Message

We are at a critical juncture. While best estimates conclude that vaccines have saved more than 150 million lives in the past 50 years, the potential for their impact for future decades is increasingly threatened by another type of contagion: misinformation. Both misinformation and disinformation travel faster and further than truth. And their potential consequences include reversals of hard-won gains in vaccine coverage and disease control established over these decades.

Vaccines have long been one of the most powerful tools in public health. They are arguably the most cost-effective public health intervention available. They save more than five lives every minute, protect against severe disease and disability, reduce the burden on health systems, protect families from sinking into extreme poverty, and contribute to economic growth. Thanks to global vaccination efforts, over 18 million people who would have been paralysed by polio can walk today, over 90 million children who would have died from measles are alive, and more than a million deaths now and in the years to come from cervical cancer have already been averted. Tens of millions more who would have suffered severe disease, some with lifelong disabilities, from meningitis, pneumonia, whooping cough, congenital rubella, rotavirus diarrhea, diphtheria, tetanus, hepatitis B, and more, have never suffered those fates. And yet, we are risking the erosion of decades of progress—not because we lack safe and effective vaccines, nor because of a lack of innovation or commitment to vaccines, but because of misinformation.

The consequences of vaccine misinformation are not hypothetical—they are real and tragic. There have been several recent cases of healthy children who died after contracting the highly contagious measles virus, or from complications of measles that can emerge years after recovery from a measles infection. Childhood vaccination rates in some countries that had previously had very high rates are dropping to levels not seen in many years. These national figures hide the fact that coverage in some communities is substantially below even the national average and far below the 95% threshold needed to maintain herd immunity. This drop in coverage, particularly for the measles vaccine, is driving a significant rise in measles cases and deaths, including in wealthy countries like the US, Canada, the UK and other European countries.

In 2024, 14.5 million infants worldwide missed out on getting even a single dose of vaccine in the essential immunization programme, according to the latest WHO-UNICEF estimates . These are "zero-dose" children—many living in fragile settings where access to care is limited and misinformation contributes an added threat.

The tactics of anti-vaccine narratives are disturbingly familiar: they often promote conspiracies that portray governments, scientists, or pharmaceutical companies as corrupt; rely on spokespeople who claim to have expertise, who discredit legitimate science; cite cherry-picked studies that ignore the overwhelming majority of scientific evidence and consensus; misrepresent safety data especially from passive surveillance systems; set impossible targets that vaccines be 100% effective and have no risks no matter how rare; and use misrepresentations or flawed analogies designed to provoke emotional reactions rather than informed understanding.

While fact-checking and scientific evidence matter, research shows that once people are exposed to falsehoods, they often continue to rely on them—even after being shown the facts.

This is an issue of influence, not of ignorance. Misinformation is increasingly driven from the top, with prominent influencers pushing thoroughly debunked myths, such as the disproven and false claim that the MMR vaccine causes autism. Pseudoscience, false logic, and selective "evidence" are weaponized in ways that sow confusion and doubt among well-meaning parents.

SAGE: Strengthening science

At WHO, the Strategic Advisory Group of Experts (SAGE) plays a pivotal role in ensuring that vaccination policies are grounded in the best available evidence. SAGE uses the Evidence to Recommendations (ETR) approach, which transparently specifies how evidence on efficacy, safety, cost-effectiveness, burden of disease, programmatic feasibility, acceptability, and other elements contributed to policy recommendations. In its upcoming September meeting, SAGE will provide guidance on immunization in emergencies and fragile settings, new vaccine introductions, addressing zero-dose children and equity gaps, and monitoring adverse events while reinforcing vaccine safety systems.

These recommendations are essential inputs for national governments navigating complex decisions amid rising skepticism.

In an era where public discourse is fragmented and science is increasingly politicized, bodies like SAGE are guardians of scientific integrity. Their role is more vital than ever—not only to guide policy but to reinforce public confidence in the institutions whose job it is to protect and promote health.

How do we respond to the emerging challenges of today? Any action must be rooted in listening to public concerns, and family concerns. It must actively counter disinformation at its source, which includes collaborating with social scientists to understand the complex dynamics that fuel hesitancy and other causes of low uptake. Transparency, especially in moments of uncertainty, is more essential than ever. We must support all programme stakeholders to share accurate information about vaccination: health professionals, local advocates and champions, and other partners such as teachers, journalists, and youth leaders.

Our collective responsibility is clear: to protect evidence-based decisions as fiercely as we protect lives. Supporting and restoring trust—one conversation, one policy, and one truth at a time, is at the core of the challenges ahead.