Why Mistrust—Not Safety Concerns—Keeps People Unvaccinated Against COVID-19

Vaccine hesitancy driven by mistrust in health authorities and low-risk beliefs is the strongest predictor of remaining unvaccinated, according to a landmark study of over 1.1 million adults in England. Researchers found that people who doubted vaccine developers or believed COVID-19 wasn't a personal threat were far more likely to refuse vaccination long-term than those with safety or effectiveness concerns—a finding that could reshape how future vaccination campaigns are designed.

What Makes Some People Permanently Resistant to Vaccination?

Scientists at the University of Manchester and other institutions analyzed survey data from over 1.1 million English adults collected between January 2021 and March 2022, then tracked 24,229 hesitant participants through May 2024 using National Health Service (NHS) records. The results, published in The Lancet, reveal a critical distinction: not all vaccine hesitancy is created equal.

Among hesitant participants who were followed over time, 65% eventually received at least one COVID-19 vaccine dose. But the remaining 35% who stayed unvaccinated shared something in common—they weren't simply worried about side effects or unsure about effectiveness. Instead, their hesitancy was rooted in deeper mistrust.

Which Attitudes Predict Lasting Vaccine Refusal?

The researchers identified eight distinct categories of vaccine hesitancy reasons and discovered that some attitudes shift over time while others stubbornly persist. The findings challenge common assumptions about what drives vaccine resistance:

• Generalized anti-vaccine sentiment: People who opposed vaccines in general were more than three times more likely to remain unvaccinated, making this the single strongest predictor of persistent refusal.
• Belief that COVID-19 impact was exaggerated: Those who thought the pandemic's severity was overstated had 3.21 times higher odds of staying unvaccinated, suggesting risk perception plays a central role.
• Distrust in vaccine developers: Skepticism about pharmaceutical companies' motives increased the odds of persistent nonvaccination by 2.63 times.
• Perception of low personal risk: People who believed COVID-19 wasn't a threat to them personally were 2.19 times more likely to refuse vaccination long-term.

In stark contrast, people who reported concerns about vaccine effectiveness or safety—while common—were generally more willing to eventually accept vaccination once they received more information or saw real-world evidence.

"Our findings will help future vaccination roll-outs to successfully target awareness campaigns and expedite vaccine acceptance," the study authors concluded, emphasizing that hesitancy rooted in concrete questions can shift as information accumulates, whereas mistrust-based hesitancy requires more tailored, community-specific strategies.

Who Was Most Likely to Remain Hesitant?

Beyond attitudes, certain demographic and socioeconomic factors made persistent vaccine refusal more likely. People with lower educational attainment, those who were unemployed, current smokers, and individuals who reported a suspected but unconfirmed prior COVID-19 infection were all significantly more likely to remain unvaccinated.

Age also mattered: younger adults aged 18 to 24 showed markedly higher hesitancy rates compared with those aged 55 to 64, and women reported higher hesitancy than men. People living in the most deprived areas were 43% more likely to be hesitant than those in mid-range deprivation areas.

During the initial rollout period, vaccine hesitancy in England peaked at 8% in early 2021 before dropping to just 1.1% at the start of 2022. However, it rebounded to approximately 2.2% in early 2022, suggesting that mistrust-driven hesitancy can resurface even after vaccination campaigns have made progress.

The most commonly cited reasons for hesitancy—concerns about long-term health effects (40.7%), uncertainty about vaccine effectiveness (38.9%), and concerns about adverse effects (36.8%)—actually declined over time and were not strong predictors of ongoing refusal. This suggests that public education addressing these specific concerns can be effective, but only for people whose hesitancy isn't rooted in fundamental distrust.

For public health officials planning future vaccination campaigns, the message is clear: a one-size-fits-all approach won't work. Addressing safety and effectiveness concerns through traditional awareness campaigns may convince people with practical questions, but reaching those driven by mistrust will require building trust within communities, engaging trusted local voices, and developing strategies tailored to specific populations and their underlying concerns.