BackgroundThe success of the COVID-19 vaccination roll-out depended on clear policy communication and guidance to promote and facilitate vaccine uptake. The rapidly evolving pandemic circumstances led to many vaccine policy amendments. The impact of changing policy on effective vaccine communication and its influence in terms of societal response to vaccine promotion are underexplored; this qualitative research addresses that gap within the extant literature.MethodsPolicy communicators and community leaders from urban and rural Ontario participated in semi-structured interviews (N= 29) to explore their experiences of COVID-19 vaccine policy communication. Thematic analysis was used to produce representative themes.ResultsAnalysis showed rapidly changing policy was a barrier to smooth communication and COVID-19 vaccine roll-out. Continual amendments had unintended consequences, stimulating confusion, disrupting community outreach efforts and interrupting vaccine implementation. Policy changes were most disruptive to logistical planning and community engagement work, including community outreach, communicating eligibility criteria, and providing translated vaccine information to diverse communities.ConclusionsVaccine policy changes that allow for prioritized access can have the unintended consequence of limiting communities’ access to information that supports decision making. Rapidly evolving circumstances require a balance between adjusting policy and maintaining simple, consistent public health messages that can readily be translated into action. Information access is a factor in health inequality that needs addressing alongside access to vaccines.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-023-15861-y.