The science and politics of vaccine hesitancy

The science and politics of vaccine hesitancy | Photo: Nappy

Published on 17 July 2026 at 06:19 GMT

By Editorial Team SDG3

Vaccine hesitancy, defined by the World Health Organization (WHO) as a delay in acceptance or refusal of vaccines despite availability of vaccination services, has emerged as a significant obstacle to public health goals in many countries. While the majority of people globally accept vaccines, declining vaccination rates in some populations and settings are creating pockets of low immunity that allow preventable diseases to return. Understanding the causes and consequences of vaccine hesitancy requires moving beyond assumptions of ignorance and engaging with the complex social, political and institutional factors that shape health behaviour.

The consequences are measurable. The WHO and UNICEF have documented resurgences of measles in countries that had previously achieved elimination status. Measles outbreaks have occurred across Europe, the Americas and parts of Africa and Asia in contexts where vaccination coverage fell below the 95 per cent threshold generally considered necessary for herd protection. Polio, a disease close to global eradication, has re-emerged in settings with gaps in immunisation coverage. These developments represent genuine reversals of public health progress.

Vaccine hesitancy is not a single phenomenon. It ranges from specific concerns about particular vaccines to broader scepticism about the pharmaceutical industry, health authorities or government recommendations. Research consistently finds that hesitancy is influenced by a combination of confidence in vaccines and the systems that deliver them, convenience of access, and complacency about disease risk in settings where diseases have become rare.

Historical trust deficits matter. Communities that have experienced medical mistreatment, exploitation in clinical research or systematic health system failures may be less willing to accept public health recommendations. The Tuskegee syphilis study, conducted for decades by United States government researchers, and documented examples of unethical drug trials in other settings, have left lasting legacies of distrust in specific communities. Acknowledging these historical contexts is not an endorsement of current hesitancy but a precondition for effective engagement.

The social environment in which health decisions are made shapes individual choices. Vaccination decisions in many communities reflect the norms and behaviours of family members, religious leaders, community networks and trusted peers rather than direct engagement with scientific evidence. Communication strategies that ignore these social networks and attempt to influence individuals through information alone tend to be less effective than approaches that engage trusted community voices.

Political polarisation has increasingly intersected with vaccine attitudes in some countries. In the United States and parts of Europe, vaccine acceptance has become associated with partisan identity in ways that create new challenges for public health communication. When health recommendations become politically coded, responses to them can be driven as much by political identity as by perceived health benefits. The European Centre for Disease Prevention and Control (ECDC) has monitored declining vaccination rates in several European countries alongside rising polarisation around public health measures.

The COVID-19 pandemic had complex and divergent effects on vaccine hesitancy. Rapid vaccine development and deployment demonstrated the capacity of modern science and public health systems. At the same time, the pandemic also intensified distrust in some populations, amplified misinformation, created new concerns about vaccine safety and generated politicised disputes about mandates, freedoms and institutional authority. Research suggests that COVID-19 vaccine hesitancy was higher in some groups that had previously accepted routine vaccination, partly reflecting new concerns about speed of development and political context.

Misinformation plays a significant role in shaping vaccine-related beliefs. False claims about vaccine composition, undisclosed side effects, concealed adverse events and links to diseases including autism have circulated across social media platforms, online communities, alternative health networks and some political media. The persistence of the claim that measles vaccination causes autism, originating from a fraudulent study retracted from The Lancet in 2010, illustrates how misinformation can persist long after its scientific basis has been thoroughly discredited.

Addressing misinformation requires approaches that go beyond factual correction. Research in psychology and communication suggests that simply repeating false claims to correct them can sometimes reinforce them. More effective approaches include prebunking, which involves educating people about misleading rhetorical techniques before they encounter them, addressing the underlying concerns and values that make specific claims attractive, and supporting trusted community messengers rather than relying primarily on institutional health authorities.

Healthcare providers remain among the most trusted sources of vaccine information in many settings. A recommendation from a personal doctor or nurse is consistently associated with higher vaccine uptake in research studies. Health system investment in training providers to discuss vaccine concerns confidently, respectfully and empathetically is therefore a high-value intervention. Providers who dismiss concerns or respond defensively can increase hesitancy rather than reduce it.

Access barriers overlap with attitudinal hesitancy in ways that complicate measurement and intervention. A parent who does not vaccinate a child may face practical obstacles including inconvenient clinic hours, transport costs, difficulty taking time off work or language barriers, as well as having concerns about vaccine safety. Surveys that measure vaccine attitudes may identify people as hesitant when their non-vaccination partly reflects systemic access failures. Effective responses need to address both barriers simultaneously.

Mandates have been implemented in several countries as a response to declining vaccine uptake. Evidence on their effectiveness is mixed. Strict mandates with meaningful consequences have increased vaccination rates in some settings. However, poorly designed or communicated mandates can also increase distrust, create backlash among those who feel coerced and reduce the social legitimacy of vaccination programmes. The WHO Strategic Advisory Group of Experts on Immunization has generally recommended exhausting non-coercive approaches before resorting to mandates.

The Lancet Commission on Vaccine Refusal, Acceptance and Demand in the United States concluded that approaches to vaccine hesitancy should focus on building trust rather than dismissing concerns, personalising communication to address the specific values and questions of different communities, and investing in the social infrastructure through which health information and norms are shared. These recommendations reflect a broader shift in thinking from information delivery to relational engagement.

Platform responsibility is an ongoing area of policy debate. Social media platforms have implemented policies to reduce the visibility of vaccine misinformation and remove the most egregious false content in some cases. The effectiveness of these measures varies, enforcement is inconsistent, and content removed from one platform may migrate to others with fewer restrictions. Algorithmic amplification of emotionally engaging and divisive content has contributed to the spread of health misinformation, raising questions about platform design and accountability.

International dimensions of hesitancy are increasingly important. Networks that spread vaccine misinformation operate across national borders, and movements that resist public health measures in one country can influence attitudes in others. At the same time, health communication strategies that work well in one cultural context may not transfer effectively to others. Building global capacity for contextually appropriate health communication requires investment in local research, media literacy and community engagement.

The relationship between vaccine hesitancy and broader health system trust is bidirectional. Experiences of poor-quality care, perceived discrimination in health services, failures to investigate reported adverse events adequately and responses that prioritise institutional reputation over patient concerns can all reduce trust in health systems generally. Strengthening pharmacovigilance systems to detect and transparently report adverse events, improving channels for community feedback and addressing documented inequalities in health system treatment of different groups are investments in the trust that underpins vaccination programmes.

Religious and cultural considerations intersect with vaccine acceptance in complex ways. Most major religious traditions have endorsed vaccination as consistent with their values. However, specific communities within different faith traditions have developed hesitancy around particular vaccines or vaccination programmes, sometimes linked to concerns about vaccine composition, production processes or perceived conflicts with religious obligations. Effective engagement requires genuine dialogue with religious and cultural leaders rather than blanket characterisations.

The public health goal is not to eliminate all critical thought about vaccines. Side effects do occur, vaccination programmes have made mistakes, and vaccine development under commercial pressure can create genuine conflicts of interest. A health system that responds to legitimate safety concerns with transparency, invests in independent safety monitoring and engages honestly with uncertainty is more likely to sustain public trust than one that treats all questions as obstacles to address.

Vaccine hesitancy sits within the broader context of SDG 3 (good health and well-being), which encompasses targets related to ending preventable deaths from communicable disease and achieving universal health coverage. Vaccination is among the most cost-effective public health interventions available. The return of measles and the stalling of polio eradication in some regions demonstrate that hesitancy is not merely a sociological curiosity but a public health risk with real consequences.

The long-term trajectory of vaccination programmes depends on maintaining the social and institutional foundations of public trust. This requires health systems that are genuinely responsive to communities, communication strategies grounded in respect for diverse values and concerns, transparent governance of vaccine development and safety monitoring, and investment in addressing the access barriers and systemic inequalities that overlap with attitudinal hesitancy. Information alone has never been sufficient to sustain high vaccination rates in diverse, complex societies.

Further information:

* World Health Organization, the global health authority provides resources on vaccine hesitancy, the SAGE working group definitions, vaccination coverage data and global immunisation strategies. https://www.who.int/health-topics/vaccines-and-immunization

* UNICEF, the United Nations children’s fund monitors vaccination coverage, childhood immunisation and access barriers across low- and middle-income countries. https://www.unicef.org/health/immunization

* European Centre for Disease Prevention and Control, the EU public health agency monitors vaccination coverage, disease outbreaks and hesitancy indicators across member states. https://www.ecdc.europa.eu/en/immunisation-vaccines

* Lancet Commission on Vaccine Refusal Acceptance and Demand, the commission published a major assessment of vaccine hesitancy in the United States with broader implications for communication and trust-building. https://www.thelancet.com/commissions/vaccine-demand-US