Vaccine skepticism can often be overcome, according to a British study published in The Lancet. Matthew Whitaker, PhD, research associate in computational epidemiology at Imperial College London in London, England, and his team found that nearly two thirds of people who initially expressed reservations about COVID vaccination were eventually vaccinated during the campaign.

Whitaker and his team analyzed longitudinal data from 1.1 million adults (age, 18 years or older; 57% female) drawn from one of the world’s most comprehensive COVID-surveillance studies, the REACT study. The survey began with the introduction of the first COVID vaccines in January 2021 and ended in March 2022. Vaccination status was known for a large share of participants. For those who initially did not get vaccinated, subsequent entries in the UK vaccination registers were checked with consent.

The analysis showed that reluctance was highest early in the campaign. In January 2021, 8% of respondents still expressed doubts about vaccination; by early 2022, that figure had fallen to just more than 1%. Vaccine skepticism rose briefly again during the Omicron wave, the authors reported.

The most common reasons for initial hesitation were concerns about potential side-effects and doubts about vaccine effectiveness. Many people with these concerns later changed their minds and went on to get vaccinated, the authors noted. By contrast, people who distrusted vaccination in principle — those who said they generally rejected vaccines, did not trust the manufacturers, or regarded COVID as a low risk — were more likely to remain unvaccinated.

Gender Differences in Risk Perception

“The results showed that different population groups were skeptical about vaccines for different reasons,” said Berit Lange, MD, head of the Department of Epidemiology at the Helmholtz Centre for Infection Research in Braunschweig, Germany, in her comments to the Science Media Center Germany. While women more often worried about fertility and younger participants more often reported “fear of pain or needles,” men tended to classify COVID as a lower risk.

Particularly younger people and those who did not perceive COVID as a risk, or who had a generally negative attitude toward vaccines, were more likely actually to remain unvaccinated if they were initially vaccine-skeptical, Lange added.

Whitaker and colleagues’ analysis links social and psychological influences on vaccination decisions with objective health data from the UK health system. “This allows for a very precise understanding of which attitudes are related to behavior,” said Sarah Eitze, PhD, member of the Institute for Planetary Health Behavior at the University of Erfurt in Erfurt, Germany. The study provides important insights into how different forms of skepticism, risk assessment, and trust are associated with real vaccination behavior, she said.

Overall, the share of people classified as generally vaccine-skeptical in the study appears lower than their presence on social media would suggest, said Klaus Überla, director of the Harald zur Hausen Institute for Virology at University Hospital Erlangen, Erlangen, Germany. “However, due to the study design, it cannot be ruled out that those who are particularly skeptical of vaccination did not participate, leading to underreporting,” he added.

Überla said he was surprised to find persistent vaccine skepticism more often among people older than 75, a group that was particularly vulnerable to COVID. “We may need new ways to reach the elderly,” he said.

Failures in Risk Communication

How transferable are the British results to Germany and other countries? Lange noted that transferability depends on local conditions and the current epidemic situation, making direct comparisons difficult.

Comparing the findings with Germany’s COSMO study, a long-running survey tracking public perceptions during the pandemic, Eitze said she observed similar underlying patterns, particularly the relationship between trust in institutions and willingness to vaccinate. However, she noted that political polarization, federal responsibilities, and a protest movements, such as Germany’s “Querdenken” movements, may play a more prominent role in Germany than in the UK context.

Although vaccination prevented millions of deaths worldwide, public discussion has been dominated byconcerns about the waning durationof COVID vaccine effectiveness and largely speculative safety risks of mRNA vaccines. Communication failed to successfully explain the evolving findings on the effectiveness of COVID vaccines and to answer legitimate public questions.In trying to simplify the message, some information was communicated incorrectly, Überla said.

For example, public messaging often emphasized that vaccination did not prevent infection with the Omicron variant while noting it protected against severe disease. In fact, protection against infection with the Omicron variant after the third dose is about 40%, according to a large meta-analysis. Moreover, the assertion that vaccines did not prevent infection was sometimes equated with a claim that they did not reduce onward transmission.

In fact, Überla explained, protection against transmission combines the reduced risk for infection and a lower infectiousness among vaccinated people who become infected, Überla noted. Estimates place the reduction in infectiousness at about 30%, meaning that three vaccine doses reduce transmission risk overall by roughly 60%. Because viral spread is exponential, even a moderate reduction in transmission risk can substantially lower the number of concurrent infection events.

Tailor Messages to Different Audiences

In retrospect, Überla said there are many lessons to learn from how vaccine effectiveness and safety of the COVID vaccines were communicated, and the study points out that many vaccine-skeptical people are open to new findings. 

The study suggests considering target-group and epidemic-phase-specific communication in vaccination strategies, Lange said. “This means informing and advising different groups regarding their questions and concerns at different stages of an epidemic,” Lange said.

Katharina T. Paul, PhD, head of the KNOW-VACC project at the University of Vienna in Vienna, Austria, emphasized the importance of differentiating between different types of vaccines. “With seasonal vaccinations against influenza and COVID, we are observing the effect of vaccine fatigue, not necessarily vaccine skepticism.” For childhood vaccinations, however, skepticism may be more fundamental, driven by concerns about safety or unfavorable cost-benefit perceptions.

Paul argued that political campaigns should therefore not only offer information but also build trust. Vaccination offerings also need to be optimized and made more accessible. “Doctors’ office hours, public vaccination centers, businesses, and employers play key roles in providing low-threshold access,” Paul emphasized. For risk groups such as pregnant women, additional resources in communication and the use of midwives and gynecologists are needed.

Moral pressure to get vaccinated is not particularly effective — transparent, continuous, and evidence-based information delivery is, Eitze said. “Science should explain in an understandable way what it knows — and also what it doesn’t yet know. The media play a central role in contextualizing this information and making it accessible.”

This story was translated from Medscape’s German edition.