Vaccination Requirement for Long term Travellers

USA L1, L2 Visa
1

Will it be mandatory for people travelling for long term (2-3 years) to be fully vaccinated only with FDA or WHO approved vaccines or it is only for tourist Visa?

2

It applies to any non-immigrant wanting to travel irrespective of the visa type.

https://travel.state.gov/content/travel/en/traveladvisories/ea/requirements-for-air-travelers-to-the-us.html