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GPT-5Sep 28, 2026openai/gpt-5-2025-08-07
Are vaccines an effective tool to prevent disease?
Yes. Vaccines are one of the most effective and safest tools we have to prevent infectious disease.
Why they work
•They train your immune system to recognize a germ so you can fight it off quickly on future exposure, preventing illness or making it much milder.
•High vaccination coverage also protects people who can’t be vaccinated (herd protection).
Evidence at a glance
•Smallpox was eradicated worldwide through vaccination.
•Polio has been reduced to a tiny fraction of its former global burden.
•Routine vaccines dramatically cut illnesses like measles, whooping cough, Hib, and hepatitis B, and HPV vaccines prevent many cervical and other cancers.
•Even when they don’t fully block infection (for example, some seasons of influenza), vaccines substantially reduce severe disease, hospitalization, and death.
Safety
•Vaccines are rigorously tested and continuously monitored.
•Most side effects are mild and temporary (e.g., sore arm, low fever); serious adverse events are very rare. For nearly all recommended vaccines, benefits far outweigh risks.
If you’re curious about a specific vaccine—disease, age group, effectiveness, or side effects—tell me which one and I can give details tailored to that case.