What Drives Vaccine Hesitancy and How to Address It

Vaccine hesitancy is the delay in acceptance or refusal of vaccines despite their availability, and it operates on a spectrum rather than as a binary choice between pro- and anti-vaccine camps. The World Health Organization’s working group on the topic identified three broad drivers: confidence in the vaccine and the system delivering it, complacency about the diseases vaccines prevent, and convenience of actually getting the shot. In practice, though, the reasons people hesitate are tangled up with politics, psychology, personal history, and what they encounter online, making it one of the more stubborn public health challenges of the past two decades.

The Three Cs and Why Confidence Dominates

The most widely used framework for understanding vaccine hesitancy breaks it into confidence, complacency, and convenience. Confidence refers to trust in the vaccine itself, in the healthcare system administering it, and in the policymakers recommending it. Complacency describes the feeling that the disease being prevented is not serious enough to bother with vaccination. Convenience captures the practical barriers: clinic hours, travel distance, cost, or simply not knowing where to go. The WHO’s Strategic Advisory Group of Experts defined vaccine hesitancy along these lines, emphasizing that it varies across time, place, and specific vaccines.

1PubMed. Vaccine hesitancy: Definition, scope and determinants

When researchers have tried to measure these three dimensions with survey tools, confidence consistently overwhelms the other two. Field testing of the WHO hesitancy survey found that the Likert-scale questions primarily captured confidence-related attitudes and did not correlate well with complacency or convenience.

2PubMed Central. Measuring vaccine hesitancy: Field testing the WHO SAGE Working Group on Vaccine Hesitancy survey tool in Guatemala

That matters because it tells us where most of the action is. The people who show up as “hesitant” in surveys are overwhelmingly expressing a trust problem, not a logistics problem. Convenience barriers are real and fixable with scheduling changes and mobile clinics, but they tend to show up as low uptake without the attitudinal resistance that defines hesitancy. The harder challenge is the person who has access, knows the vaccine exists, and still does not want it.

Cognitive Biases That Make Hesitancy Feel Rational

Vaccine hesitancy is not just about what people believe; it is also about how they think. Several well-documented cognitive patterns push people toward skipping vaccines even when they cannot articulate a specific objection. Omission bias is the tendency to judge harm caused by action (getting a shot that causes a side effect) as worse than harm caused by inaction (catching a disease you could have prevented). Naturalness bias is a preference for “natural” immunity over what is seen as artificial intervention. A study on influenza vaccination found that people who exhibited these biases were significantly less likely to accept the flu vaccine.

3PubMed. Do decision biases predict bad decisions? Omission bias, naturalness bias, and influenza vaccination

A scoping review of cognitive biases related to vaccination found that some people place a higher value on innate immunity than on artificially induced protection, treating vaccination as an inferior or unnatural way of achieving something the body should handle on its own.

4PubMed Central. Mapping the Cognitive Biases Related to Vaccination: A Scoping Review of the Literature

There is even an evolutionary angle. Research drawing on the behavioral immune system, the set of psychological mechanisms that evolved to help humans avoid pathogens, found that people with higher disgust sensitivity tend to hold more negative attitudes toward vaccines. The logic is counterintuitive: you might expect someone more worried about germs to want vaccination, but injecting a foreign substance triggers the same avoidance instinct that evolved to keep us away from contaminated food or sick individuals.

5Social Psychological and Personality Science. The Behavioral Immune System and Attitudes About Vaccines

These biases are not signs of ignorance. They are mental shortcuts that served humans well in other contexts but misfire when applied to modern medicine. Recognizing that they exist is part of why simply giving people more facts often fails to change their minds.

Institutional Distrust and Its Roots

For many communities, vaccine hesitancy is less about the vaccine and more about who is recommending it. Medical mistrust, the feeling that the healthcare system does not have your best interests at heart, is a powerful predictor of whether someone will get vaccinated. A longitudinal study of U.S. adults found that after accounting for demographics and COVID-related variables, people with greater medical mistrust were more likely to be vaccine-hesitant, and that perceived discrimination and mistrust together helped explain racial and ethnic gaps in vaccination.

6PubMed Central. Medical Mistrust, Perceived Discrimination, and Race: a Longitudinal Analysis of Predictors of COVID-19 Vaccine Hesitancy in US Adults

Research specifically examining Black, Asian, and Latino communities during COVID-19 found that both individual-level medical mistrust and group-based mistrust (the sense that your racial or ethnic group is treated unfairly by medicine) were significantly associated with lower vaccination intent across all three groups.

7PubMed Central. Medical Mistrust, COVID-19 Stress, and Intent to Vaccinate in Racial–Ethnic Minorities

This distrust did not emerge from nowhere. Historical abuses like the Tuskegee syphilis study, forced sterilization programs, and ongoing disparities in healthcare quality have given communities of color rational reasons to be wary. Addressing hesitancy in these populations requires grappling with that history rather than dismissing their concerns as misinformation.

When Politics Becomes the Lens

In many countries, vaccination attitudes have become entangled with political identity to a degree that would have seemed bizarre a generation ago. An analysis of European Social Survey data from 23 countries found a statistically significant relationship between political polarization and vaccination levels: about 39% of the variation in vaccination across these countries could be explained by the degree of political polarization, measured by how closely citizens identified with ruling versus opposition parties.

8PubMed Central. Political polarization may affect attitudes towards vaccination. An analysis based on the European Social Survey data from 23 countries

In the United States, the partisan divide is stark. Research on trust in vaccine science found that conservatives consistently expressed lower trust in scientific authorities regarding vaccination while expressing greater trust in religious and political figures. The researchers noted something important: these partisan effects were actually magnified among scientifically literate individuals, meaning the gap was driven less by a knowledge deficit than by political identity shaping whom people trust.

9PubMed. Partisan Polarization and Public Trust in Vaccine Science: Mapping Cultural Authority

That finding undercuts one of the most common assumptions about vaccine hesitancy: that it is mainly a problem of not knowing enough. If better science education made people who already have strong political identities more polarized rather than less, the fix clearly is not just more pamphlets and infographics.

The Misinformation Ecosystem

Social media has not created vaccine hesitancy, but it has given it a megaphone and a business model. Research on a Taiwanese online community found that influential users in the network contributed meaningfully to the polarization of misinformation consumption, with removal of high-centrality nodes leading to decreased polarization in the network.

10JMIR Infodemiology. The Role of Influencers and Echo Chambers in the Diffusion of Vaccine Misinformation: Opinion Mining in a Taiwanese Online Community

Traditional media plays a subtler role. When journalists cover vaccine controversies by presenting “both sides” equally, even on topics where the scientific consensus is overwhelming, they create the impression that experts are divided. An experiment found that participants who read a “balanced” article about the autism-vaccine link (which has been thoroughly debunked) came away less certain that vaccines are safe, more likely to believe experts disagreed, and less willing to vaccinate future children.

11PubMed. The effect of falsely balanced reporting of the autism-vaccine controversy on vaccine safety perceptions and behavioral intentions

Then there is the money. Digital ethnography of prominent anti-vaccine influencers on Instagram revealed how they build communities around wellness identities and use anti-vaccination messaging to funnel followers toward purchasing products and services. The wellness-to-anti-vax pipeline is not accidental; it is a monetization strategy.

12International Journal of Communication. Vaccine Misinformation for Profit: Conspiratorial Wellness Influencers and the Monetization of Alternative Health

Religion as Both Barrier and Bridge

The relationship between religious belief and vaccine acceptance is far more complex than “religious people refuse vaccines.” A systematic review of studies across multiple countries found that the influence of religious leaders varied widely by context. In some places like Kazakhstan and Indonesia, religious leaders actively promoted vaccination by endorsing public health messages and participating in government campaigns. Pope Francis and several interfaith councils publicly supported COVID-19 vaccination, framing it as a moral responsibility.

13PubMed Central. The role of religious leaders in the acceptance of COVID-19 vaccinations: a systematic review

At the same time, specific religious objections do create resistance. A scoping review of HPV vaccine attitudes in Islamic countries found significant objections among some Muslims, including beliefs that vaccines cause infertility, encourage sexual promiscuity, contain ingredients prohibited under religious law, or represent a broader violation of religious principles.

14PubMed Central. Religious beliefs and practices toward HPV vaccine acceptance in Islamic countries: A scoping review

Qualitative research with faith communities has found that while some religious beliefs do create barriers, religion is more often a facilitator of vaccine uptake because of its emphasis on protecting oneself and one’s community. The deeper barriers within religious communities tend to be about mistrust, feelings of stigma, and tokenistic engagement by health authorities who approach faith groups only after deeming them hesitant rather than involving them early.

15PubMed. Enhancing faith and interfaith based facilitators and reducing related barriers to enhance vaccine acceptance: a qualitative study

What Declining Coverage Actually Costs

Vaccine hesitancy is not just an attitude; it has measurable consequences. A modeling study estimated that a five-percentage-point decline in MMR vaccine coverage among U.S. children aged two to eleven would lead to roughly a threefold increase in annual measles cases in that age group and an additional $2.1 million in public-sector costs.

16JAMA Pediatrics. Public Health and Economic Consequences of Vaccine Hesitancy for Measles in the United States

That five-point drop sounds small, but measles is extraordinarily contagious, and even modest coverage gaps in specific communities can allow outbreaks. The broader picture is that reduced vaccine coverage has led to a resurgence of vaccine-preventable diseases, threatening decades of public health progress.

17PubMed Central. Measles Resurgence and the Fragility of Herd Immunity: Implications for Pediatric Infectious Disease Practice

Globally, the pattern is not uniform. In low- and middle-income countries, about one in five adults reported being hesitant about the COVID-19 vaccine, with safety concerns as the top reason followed by doubts about effectiveness.

18BMJ Open. How prevalent is COVID-19 vaccine hesitancy in low-income and middle-income countries and what are the key drivers of hesitancy? Results from 53 countries Prior research has found that while hesitancy in high-income countries tends to be more common among affluent groups, the relationship between socioeconomic status and hesitancy in lower-income countries is less clear, and education level was not significantly linked to hesitancy.19PubMed Central. Comparisons of Vaccine Hesitancy across Five Low- and Middle-Income Countries

Approaches That Move the Needle

Given how multifaceted the problem is, no single intervention works for everyone. But several strategies have shown measurable effects.

Motivational interviewing, a technique where healthcare providers guide patients through their own reasoning rather than lecturing them, has proven effective in multiple randomized controlled trials in Canada. The approach aims to meet people where they are, respecting their beliefs while helping them articulate their own reasons for change.

20PubMed Central. Motivational interviewing: A powerful tool to address vaccine hesitancy

Simple behavioral nudges can also make a surprising difference. A field experiment found that scheduling patients by default for a flu shot appointment increased the vaccination rate by ten percentage points compared to just encouraging patients to make an appointment, with no displacement of vaccinations people would have gotten elsewhere.

21PubMed Central. Default clinic appointments promote influenza vaccination uptake without a displacement effect Text-message nudges designed to make vaccination feel easy and top-of-mind boosted COVID-19 appointment rates by about 86% and actual vaccination rates by about 26% relative to the control group in a randomized trial.22medRxiv. Behavioral nudges increase COVID-19 vaccinations: Two randomized controlled trials

Prebunking, the idea of inoculating people against misinformation before they encounter it, is a newer strategy with promising results. A series of three randomized trials involving over 2,300 participants found that playing a game designed to expose the manipulation techniques behind vaccine misinformation significantly improved people’s ability to distinguish misinformation from accurate information and made them more confident in spotting manipulative content.

23Scientific Reports. Psychological inoculation improves resilience to and reduces willingness to share vaccine misinformation

Mandates and the Reactance Problem

Vaccine mandates are among the most debated policy tools. Critics warn that forcing people to get vaccinated triggers psychological reactance, a defensive response to perceived threats to personal freedom, and ultimately backfires. The evidence is more nuanced than either side suggests.

A careful analysis across multiple studies found little support for the idea that mandates, vaccination passports, and financial incentives backfire at the population level. These policies can effectively promote vaccination overall.

24PubMed Central. Do COVID-19 Vaccination Policies Backfire? The Effects of Mandates, Vaccination Passports, and Financial Incentives on COVID-19 Vaccination

But that does not mean reactance is imaginary. Experimental research found that mandates including sanctions produced significantly greater perceptions of freedom threat than mandates without sanctions.

25PubMed. Psychological Reactance Theory and COVID-19 Vaccine Mandates: The Roles of Threat Magnitude and Direction of Threat Another study found that reactance from mandates could decrease intention to vaccinate against influenza and reduce adherence to other protective measures.26PubMed Central. Vaccination policy reactance: Predictors, consequences, and countermeasures The picture that emerges is that mandates tend to increase overall vaccination numbers, but the minority who feel coerced can become more entrenched in their opposition and may resist public health measures more broadly. Policymakers face a genuine trade-off between population-level coverage gains and the deepening of hesitancy among a smaller group.

How COVID-19 Changed Attitudes Toward Routine Childhood Vaccines

One of the most concerning legacies of the pandemic is whether the polarizing debate over COVID-19 vaccines has spilled over into attitudes about routine childhood immunizations. A study using nationally representative U.S. survey data found that overall parental vaccine hesitancy did not significantly change from the pre-pandemic period through the pandemic and post-vaccine rollout periods. That is the reassuring finding. The worrying one is that parents became significantly less sure about trusting the information they receive about childhood vaccines. In the post-vaccine pandemic period, parents had roughly double the odds of being “unsure” about trusting vaccine information compared to the pre-pandemic period.

27Pediatrics. The COVID-19 Pandemic and Parental Attitudes Toward Routine Childhood Vaccines

That gap between behavior and trust is a vulnerability. Parents may still be vaccinating their children for now, but the erosion of trust in vaccine information creates fertile ground for future hesitancy if another controversy or influential voice tips the scale.

When Transparency Helps and When It Backfires

A common refrain in public health is that transparency builds trust, and that is generally true but with a significant catch. A study on the U.S. Vaccine Adverse Event Reporting System found that participants who received general information about VAERS along with summary safety data showed slightly more trust in the CDC and greater HPV vaccine acceptance. But participants who were shown detailed individual adverse event reports experienced reduced trust and acceptance.

28PubMed. Can the vaccine adverse event reporting system be used to increase vaccine acceptance and trust?

The distinction matters because VAERS is an open, unverified reporting system where anyone can submit a report regardless of whether the adverse event was caused by the vaccine. Reading individual reports without understanding that context is likely to alarm rather than reassure. Research on health literacy and risk communication has explored how different formats for presenting vaccine risk-benefit information affect understanding, finding that evaluative labels (like “low risk” or “high benefit” tags) were preferred across literacy levels, and that animated explanations increased knowledge compared to standard government information.

29PubMed. Using health literacy principles to improve understanding of evolving evidence in health emergencies: Optimisation and evaluation of a COVID-19 vaccination risk-benefit calculator

The broader lesson from vaccine safety controversies, including the Dengvaxia dengue vaccine case in the Philippines that devastated public trust, is that transparency without context can do as much harm as secrecy. Integrating clear communication with robust safety surveillance is what rebuilds confidence after things go wrong.

30PubMed. From controversy to confidence: Strengthening dengue vaccines safety reporting

Vaccine Injury Compensation and What It Signals

Most people do not know that many countries have formal programs to compensate individuals who experience serious adverse effects from vaccines. These no-fault systems exist in at least 25 to 30 countries and are designed to provide quick compensation without requiring the injured person to prove negligence, removing a barrier that discourages both reporting and trust. The programs also serve a symbolic function: they acknowledge that while vaccines are overwhelmingly safe, rare injuries do occur, and society takes responsibility for them.

A review of these programs noted that while existing schemes cover routine immunizations in about 27 countries, they are not always well-defined enough to handle mass vaccination during a pandemic. The COVID-19 crisis highlighted this gap, as the rapid global rollout raised the stakes for having transparent systems that could address injuries quickly.

31PubMed Central. Current situation of vaccine injury compensation program and a future perspective in light of COVID-19 and emerging viral diseases

For hesitant individuals, the existence of these programs can be genuinely reassuring. It shifts the conversation from “vaccines are perfectly safe, trust us” to “vaccines are overwhelmingly safe, and if something does go wrong, there is a system in place.” That distinction matters to people whose hesitancy is rooted in a feeling that the system does not take their concerns seriously. The recurring themes identified in a historical overview of anti-vaccine movements, concerns about safety, distrust of institutions, and objections grounded in personal liberty, have appeared consistently from the smallpox era through COVID-19.

32PubMed. A historical overview of the anti-vaccine movement and its public health implications Compensation programs address at least the first two of those concerns by making the system’s safety net visible rather than hidden.