The obesity examples fails because obesity is non-contagious. The issue with COVID is that not getting vaccinated puts your coworkers even more at risk in an environment where you're already much more likely to be infected.
Additionally, in health care you're often working with patients who have comorbidities, for these patients, contracting COVID from a healthcare worker could be a death sentence.
Because France doesn't need to care about China but they do need to care about Russia, and they don't have the ability to counterbalance Russia without the US. This is part of why their nationalist movement to rebuilt their military is growing strength, but they're far from being capable of being independent from the US.