Decreasing vaccine hesitancy has proven to be difficult, with most vaccine-communication approaches showing modest effects at best. Nevertheless, approaches that focus on identifying subgroups for targeted messages, tailoring messages to match recipient preferences, or training healthcare professionals’ (HCPs’) communication skills have been shown to reduce vaccine hesitancy. 

The present thesis aimed to explore these approaches by 1) identifying and describing COVID-19 and influenza vaccine-hesitancy subgroups, 2) developing and investigating the efficacy of statistically and anecdotally tailored vaccine messages, and 3) evaluating the efficacy of an Empathetic Refutational Interviewing (ERI) training intervention intended for HCPs tasked with discussing vaccines with patients. Hierarchical cluster analysis was used to identify COVID-19 and influenza vaccine-hesitancy subgroups in two general population samples, the efficacy of statistical and anecdotal vaccine-promoting messages was experimentally tested in said general population samples, and the ERI training intervention was experimentally evaluated in two samples consisting of HCPs working in Finland and in the UK.

COVID-19 and influenza vaccine-hesitancy subgroups were found to share similar vaccine-hesitancy patterns, ranging from people that are more positive toward these vaccines to people that are strongly against vaccines, and with COVID-19 vaccine-hesitancy subgroups exhibiting greater variability. Statistical and anecdotal vaccine messages were found to have small to no effects on participants’ vaccine attitudes and their vaccination intentions even when the type of message matched participants’ preferences. The short ERI training scenarios showed modest yet encouraging results, suggesting that HCPs may be able to quickly learn and implement empathetic affirmations into their communication approach. 

Future research is needed on the combined effects of different vaccine-communication approaches as no single vaccine-communication approach is likely to be sufficient to address vaccine hesitancy.