The spread of SARS-CoV-2 led to rapid vaccine development. However, there remains considerable vaccine hesitancy in some countries. We investigate vaccine willingness in three nations with very different vaccine histories: Israel, Japan and Hungary. Employing an ecological-systems approach we analyse associations between health status, individual cognitions, norms, trust in government, COVID-19 myths and willingness to be vaccinated, with data from three nationally representative samples (Israel, Jan. 2021, N = 1011; Japan, Feb. 2021, N = 997; Hungary, April 2021, N = 1130). Vaccine willingness was higher in Israel (74%) than Japan (51%) or Hungary (31%). In all three countries vaccine willingness was greatest amongst who would regret not being vaccinated and respondents who trusted their government. Multi-group latent class analysis identified three groups of COVID myths, with particular concern about alteration of DNA (Israel), allergies (Hungary) and infection from the vaccine (Japan). Intervention campaigns should address such cultural myths while emphasising both individual and social benefits of vaccination.