Evaluation of an Interactive Risk Information Tool to Increase COVID-19 Vaccination Incidence in Vaccine-hesitant People During Omicron Wave in Germany

Coronavirus (COVID-19) vaccines have saved millions of lives since release and remain a key tool in the fight against the pandemic.

However, most countries have not reached the vaccine uptake rates needed to relieve pressure on hospitals and intensive care units (ICUs) during peak corona periods. Reduced effectiveness of vaccines in preventing infections with the Omicron variant and milder courses of the disease may trigger and support beliefs that vaccination is no longer necessary, especially among vaccine sceptics.The term 'vaccine sceptic', however, is used heterogeneously and often interchangeably to describe both 'vaccine hesitants' and 'vaccine deniers'. In contrast to vaccine deniers, characterized by a definite and unwavering decision not to get vaccinated, vaccine hesitants are characterized by a spectrum of indecisiveness, with a high need for information on both benefits and harms. They may still decide to get vaccinated if information succeeds in convincing them. In light of the potential for a change of mind in vaccine-hesitants the key question is: How does one best address their high needs for balanced risk ratio information? Evidence from cognitive and behavioral science suggests that interactive simulations of risk information, which imitate mechanisms by which humans sequentially and experientially sample risk information naturally, can be more effective in helping people develop adequate risk perceptions and initiate behavioral change than the ubiquitously used conventional text-based formats. The study therefore seeks to determine if interactive risk ratio simulation relative to a text-based format are more effective in prompting positive change in unvaccinated, vaccine-hesitant respondents' intention to get the COVID-19 and also in the respective benefit-to-harm ratio assessment during the Omicron wave in Germany.