U.S. Opens Its Borders … But Only to the Vaccinated

The US is reopening its borders with Canada and Mexico in November, allowing tourists and separated families to enter after a 19-month closure. However, only fully vaccinated individuals will be permitted entry. Unvaccinated travelers will still be banned, and those who were previously exempt, like commercial drivers and students, must show proof of vaccination starting in January.

Who are the individuals that were never banned from traveling across the land borders?

What is the purpose of requiring proof of vaccination for commercial drivers and students starting in January?