"They need to speak a language everyone can understand": Accessibility of COVID-19 vaccine information for Canadian adults with intellectual and developmental disabilities.

Accessible vaccine information is one vital component of effective vaccination programs, however, there is limited research that explores how people with disabilities engage with public health messaging. This study aimed to understand how adults with intellectual and developmental disabilities (IDD) and their caregivers navigated Canada's public health communications regarding COVID-19 vaccines. A national survey on the accessibility of vaccine information was conducted in the spring and summer of 2022. Surveys were completed by 208 adults with IDD, 102 family caregivers and friends, and 54 staff. Quantitative data were analyzed descriptively, and descriptive qualitative content analysis was applied to open-ended survey responses. Vaccine information was difficult to understand and was not accessible to many people with IDD and their caregivers. Approximately 75 % of adults with IDD found COVID-19-related information challenging to comprehend, followed by 69 % of family/friends and 56 % of staff. All three groups indicated they felt overwhelmed by the large quantity of information they had to navigate (adults with IDD, 72 %; family/friends, 65 %; staff, 70 %) and experienced difficulties such as finding trustworthy sources and identifying vaccine misinformation and disinformation. Respondents offered recommendations to improve public health messaging and the accessibility of future vaccine campaigns. Our study explored the experiences of Canadian adults with IDD and caregivers while navigating COVID-19 vaccine information, revealing significant barriers. To address these barriers and improve vaccine uptake, public health communications must ensure accessibility throughout every stage of immunization, including education campaigns, appointment booking, vaccination appointment, and aftercare services. Recommendations include using Easy Read language and multiple formats, supporting caregivers and community groups, and enlisting trusted community messengers to disseminate accurate information and build confidence among adults with IDD and their caregivers.