Background: In super-ageing Japan, COVID-19 vaccinations were starting to reach older people as of June 2021, which raises the issue of vaccine literacy. This study focuses on family members who work and also care for their older parents, as they are at risk of COVID-19 and also risk transmitting COVID-19 to the parents they care for and potentially influencing their parents’ vaccine uptake. Such family carers are central to the approach in Japan to achieving a sustainable and resilient society in response to ageing.