Levels of mistrust in the science behind COVID-19 vaccines have hovered at about 35% for the past 3 years among US adults, while the greatest levels of trust were seen among men, those with university degrees and high median outcomes, and those who had lost someone to COVID-19, according to an analysis of surveys published in Vaccine: X.
Researchers from the City University of New York (CUNY) and the Barcelona Institute for Global Health in Spain evaluated responses to online surveys conducted in 2021, 2022, and 2023 as part of a larger study to understand determinants of COVID-19 vaccine acceptance in 23 countries.
"As the pandemic evolved, the significance of general trust in science emerged at the forefront of public health discussions as a pivotal factor influencing vaccine uptake and particularly the willingness to receive future COVID-19 vaccine boosters," the team wrote.
People who lost someone to COVID 4 times more likely to trust
Slightly over half (50.9%) of respondents were women, and 35.7 % were university graduates. In 2023, 36.1% of participants each reported incomes above and below the US median. One-fifth (20.7%) reported no income, 31.5% said they had lost a family member or close friend to COVID-19, and 10% reported experiencing the loss within the past year.
In 2021, 2022, and 2023, 63.9%, 67.2%, and 63.8% of respondents, respectively, said they trusted science, and the differences were nonsignificant. Those proportions were lower than the global averages reported in previous studies, averages for the larger 23-country surveys, and samples from other high-income countries.
Science education in lower, middle, and high schools could be a powerful learning platform to explain the contributions of scientific thinking towards human well-being and promote science literacy.
In 2023, trust in COVID-vaccine science was significantly higher in men (adjusted odds ratio [aOR, 1.42]), university graduates (aOR, 2.37), and those with incomes higher than the median, relative to no income (aOR, 1.74).
These findings, the authors said, "suggest that science literacy needs to be fostered more vigorously among younger age and less affluent groups in our society. Science education in lower, middle, and high schools could be a powerful learning platform to explain the contributions of scientific thinking towards human well-being and promote science literacy."
Trust in science wasn't significantly correlated with age or race but was significantly higher in participants reporting the loss of someone to COVID-19 within the past year (aOR, 3.91) or more than a year ago (aOR, 2.20), relative to no such loss.
"On one hand, direct confrontation with the severity of a disease may heighten an individual's appreciation for the need for new or more effective scientific efforts to combat it, thus enhancing trust in science and the willingness to accept vaccines," the authors wrote. "On the other hand, grief and the perception of failure to protect loved ones can erode trust in the very scientific endeavors meant to safeguard the public's health."
Trust in CDC strongly tied to vaccine willingness
In 2023, 83.0% of respondents reported vaccine acceptance, and 72.2 % of vaccinees said they were willing to receive future recommended COVID-19 boosters.
Vaccine acceptance over time was consistently higher among respondents who reported loss of family member or friend to COVID-19, with 2023 acceptance at 89.9%. Those who didn't experience personal loss had significantly lower acceptance rates, especially in 2021 (63.5%), but they reached 80% in 2023.
Future research should incorporate political affiliation as a variable to better understand its impact on trust in science and vaccine acceptance, providing a more comprehensive view of the socio-political factors that shape public health behaviors.
"Personal experiences of loss due to COVID-19 were important predictors of trust in science and vaccine acceptance, highlighting the need for public health communications to be sensitive to the emotional impact of loss and grief along with the diverse socio-economic and educational backgrounds of the US population," they wrote.
Trust in the US Centers for Disease Control and Prevention (CDC) as a source of credible information about COVID-19 vaccines was significantly tied to vaccine uptake (aOR, 3.11), but it wasn't a factor after the model was adjusted for trust in vaccine science. Trust in the CDC as a source of information about COVID-19 vaccines, however, remained significantly linked to willingness to receive future recommended boosters, even after adjustment for trust in science (aOR, 3.77).
"Trust in the science behind COVID-19 vaccines appears to have been a crucial factor in US vaccine acceptance, with respondents who expressed higher trust being significantly more likely to accept the vaccine and express willingness to take future boosters," the study authors wrote.
The researchers called for strengthening trust in communications from public health officials, especially from the CDC. They also urged future longitudinal research to elucidate how trust in science evolves over time and research into the emotional and psychological mechanisms of the relationship between personal loss and vaccine acceptance.
"Future research should incorporate political affiliation as a variable to better understand its impact on trust in science and vaccine acceptance, providing a more comprehensive view of the socio-political factors that shape public health behaviors," they wrote.
In a CUNY press release, senior author Ayman El-Mohandes, MBBCh, MD, MPH, dean of the CUNY School of Public Health, said, "This research provides valuable insights for policymakers and health communicators as they continue to navigate the ongoing challenge of global vaccine hesitancy."