"Vaccinating your child during an emergency is more important than ever": a randomised controlled trial on message framing among Ukrainian refugees in Poland, 2023.

BackgroundSince February 2022, the start of the full-scale war in Ukraine, millions of women and children have fled the country. Vaccination of refugee children is important to protect this vulnerable population from disease.AimWe investigate the determinants of vaccination intention in refugee mothers from Ukraine residing in Poland and test the effect of three message frames.MethodsParticipants were randomised into either a control group or one of three intervention groups encouraging vaccination using a specific frame: (i) trust in the Polish health system, (ii) ease of access to vaccination or (iii) risk aversion. Primary outcomes were intention to vaccinate a child in Poland and clicking on a vaccination scheduling link.ResultsThe study was completed by 1,910 Ukrainian refugee mothers. Compared with the control group, the risk aversion message significantly increased vaccination intention (adjusted odds ratio (AOR): 2.35, 95% confidence interval (CI): 1.25-4.42) and clicking on the vaccine scheduling link (AOR: 1.53, 95% CI: 1.12-2.09). Messages around trust and ease of access did not have an effect. Important determinants of vaccination intention were perceived importance of vaccination (AOR: 1.12 95% CI: 1.01-1.25) and trusting vaccination information official health institutes (AOR: 1.40 95% CI: 1.06-1.83) and social media (AOR: 2.09 95% CI: 1.33-3.27).DiscussionUsing a risk aversion frame highlighting the vulnerability to infection that refugees face resulted in increased vaccination intention and clicks on a vaccination scheduler. Health workers who interact with Ukrainian refugees could use this frame in their vaccination communication.