Wait until they require vaccination records...or antibody records.
If I worked in a cubicle farm I would expect them to do that until the organization was over 85% imminently.
Any business — if there are any — that can legitimately require immunization or antibody records of its employees — is already doing that. Maybe there are companies involved in medical research in sterilized environments that can justify this. Anyone else who tries this is quickly going to be out of business.