COVID-19 vaccine acceptance increased 3.7% between 2020 and 2021, according to a new study from researchers at the CUNY Graduate School of Public Health and Health Policy (CUNY SPH), the Barcelona Institute for Global Health (ISGlobal), the Dalhousie University and the University of Calgary.

In a June 2021 survey of over 23,000 individuals across 23 countries, the researchers found that more than three-quarters (75.2%) of respondents reported vaccine acceptance, up from 71.5% one year earlier.

The study, which was published Monday in Nature Communications, was carried out within the context of a year of substantial but very unequal global COVID-19 vaccine availability and acceptance, which necessitated new assessments of the drivers of vaccine hesitancy and the characteristics of people not vaccinated.

Concerns about vaccine safety and efficacy and mistrust in the science behind vaccine development were the most consistent correlates of hesitancy. Other factors associated with vaccine hesitancy varied by country and included personal experience with COVID-19 (e.g., sickness or loss of a family member) and demographic characteristics (e.g., gender, education, and income).

The authors found that vaccine hesitancy did not significantly correlate with a country's current COVID-19 case burden and mortality. In June 2021, vaccine hesitancy was reported most frequently in Russia (48.4%), Nigeria (43%), and Poland (40.7%), and least often in China (2.4%), the United Kingdom (UK) (18.8%), and Canada (20.8%).

"In order to improve global vaccination rates, some countries may at present require people to present proof of vaccination to attend work, school, or indoor activities and events," says CUNY SPH Senior Scholar Jeffrey Lazarus. "Our results found strong support among participants for requirements targeting international travelers, while support was weakest among participants for requirements for schoolchildren."

Support for vaccine mandates was substantially lower among those who were hesitant to get vaccinated themselves. "Importantly, however, recommendations by a doctor, or to a lesser extent by an employer, might have an impact on a respondent's views on vaccination in some countries," said CUNY SPH Dean Ayman El-Mohandes.

Although some countries are currently disengaging from evidence-based COVID-19 control measures, the disease has by no means been controlled or ended as a public health threat. The authors note that for ongoing COVID-19 vaccination campaigns to succeed in improving coverage going forward, substantial challenges remain. These include targeting those reporting lower vaccine confidence with evidence-based information campaigns and greatly expanding vaccine access in low- and middle-income countries.

The role of social networks

ISGlobal and the Institute #SaludsinBulos, together with the Severo Ochoa Foundation and representatives of Spanish scientific and professional societies and patient associations, held a meeting on 20 June 2022 to advance the development of a consensus on addressing vaccine hesitancy. According to data presented from a European survey carried out by the Vaccine Confidence Project, the population group most exposed to social networks—young people under 24 years of age, with secondary or university studies and living in urban areas—are the most reluctant to be vaccinated. Additionally, messages that call for vaccination as a "moral obligation" are strongly rejected compared to those that call for "protection," which are more commonly well received.

As reflected in similar studies, one of the most popular ways of conveying anti-vaccine messages has been humor. Therefore, participants in the meeting agreed on the need to disseminate the benefits of vaccines using this same tool, but without making fun of those who have mistaken beliefs about vaccines. In the face of misinformation, it is important to improve information on vaccination using simple language and channels that reach the population, such as social networks, the participants concluded.