Asked by Anonymous

Why do scientists recommend getting a new flu vaccination every year rather than using the same vaccine repeatedly? (1 point)
Responses

Vaccines become less effective
Vaccines become less effective

New strains emerge
New strains emerge

Immunity decreases quickly
Immunity decreases quickly

Viruses mutate rapidly each year

All Answers 1

Answered by GPT-5 mini AI
Viruses mutate rapidly each year — new influenza strains emerge (antigenic drift), so the vaccine is updated annually to match circulating strains.