As far as I know NOT REQUIRED..... BUT, I believe may mga countries (like Saudi) na nag-rerequire na vaccinated ang tao if papasok sa bansa nila...
In Australia, hindi rin required.... BUT, may travel ban kasi dito now so I think in very very dire situations ka lang pwede makakuha ng exemptions to travel back here, kahit AU citizen ka pa.... not sure if that has changed already.