Vaccine requirements in the United States have a long history. States mandate childhood vaccinations as a condition of public-school attendance, with exemptions that vary by state (medical, religious, philosophical). The military has long required service members to receive specified vaccines.
The COVID-19 era expanded the debate. Federal employer mandates, healthcare-worker requirements, and military COVID vaccination orders generated litigation, Supreme Court rulings, and legislative pushback. Some states tightened school requirements; others broadened exemptions.
Open questions include the appropriate scope of employer mandates, whether religious and philosophical exemptions should be expanded or narrowed, federal vs. state authority, and how to balance public-health goals against individual choice and bodily autonomy.