My workers received their renewal notice before 1 March 2024 but their Work Permits have not yet been renewed. Do they still need to be COVID-19 vaccinated?

No. From 1 March 2024, all pass holders no longer need to fulfil the COVID-19 vaccination requirements to get their passes issued or renewed.

You can get their Work Permits renewed or S Passes issued, even if they are not fully vaccinated.