vaccination

This term describes both the medical procedure of administering a vaccine and the resulting biological status of the patient. It carries a strong connotation of preventative healthcare and public safety, often appearing in the context of large-scale health initiatives or mandatory requirements for travel and education. As a noun, it is typically used as a countable noun when referring to the individual act or a specific dose (e.g., "three vaccinations"), but can function as an uncountable noun when referring to the general concept or the state of being protected (e.g., "vaccination is key to eradication").