What sort of industry are you in, and where do you operate?
I used to work for a company that involved FIFO work to PNG, which meant more vaccinations were provided, as there was more exposure.
Now, I'm office-based here in NZ, Flu vaccine is sufficient.
Wayne Nicholl put it well. Determine exposure, determine primary controls and use vaccinations as additional controls.
Additionally, look at relevant industry standards for what is recommended/required. Also the New Zealand Immunisation Advisory Centre.
As an example, Plumbers generally require Hep A&B and IPV. Without having checked it, I believe that is even part of their registration requirement.