Vaccination Status for Pay Purposes

We have modified our STD program since March 2020 when Covid first came into play – so we have paid our employees day 1 of illness instead of a 3 days wait period.  I would like to continue doing so, but for those employees who are vaccinated only.  We have locations across the country and are not federally regulated.  Can I do this?  Im trying to encourage vaccination vs mandating it.  Thank you