openai (gpt-5-nano-2025-08-07) · supported · 90%

Vaccines have contributed to large reductions in infectious diseases globally. Historical and contemporary evidence shows major declines in diseases such as smallpox (eradicated), polio, measles, diphtheria, and pertussis where vaccines are used, though regional disparities and persistent disease burden exist.

Key points: Vaccination programs have driven substantial declines in incidence and mortality for multiple diseases worldwide. | Smallpox eradication and dramatic polio reductions illustrate the impact of vaccines; complete eradication is not universal for all diseases, but gains are real. | Measles, diphtheria, tetanus, pertussis, and other vaccine-preventable diseases have shown large reductions where vaccination coverage is high. | Public health data indicate millions of deaths are prevented annually through vaccines and immunization programs. | Regional gaps in access, coverage, and vaccine hesitancy can moderate the global impact.

Limitations: The extent of reduction varies by disease and region; some diseases persist or experience outbreaks despite vaccines. | Other factors (sanitation, nutrition, healthcare access) also contribute to disease declines and can confound attribution to vaccines alone. | Vaccine effectiveness and waning immunity can affect long-term outcomes in some contexts. | The claim is broad and does not specify which diseases or time periods; global impact is substantial but not uniform.

anthropic (claude-haiku-4-5-20251001) · supported · 95%

Extensive epidemiological evidence strongly demonstrates that vaccines have contributed significantly to substantial reductions in infectious disease burden worldwide.

Key points: Smallpox eradicated globally by 1980 through vaccination campaigns | Polio cases reduced by over 99% since routine vaccination introduction (from ~350,000 cases in 1988 to fewer than 1,000 annually in recent years) | Measles deaths declined approximately 73% globally between 2000-2018 due to vaccination | Diphtheria, tetanus, pertussis, rubella, and other vaccine-preventable diseases show dramatic reductions in vaccinated populations | Yellow fever, hepatitis B, and rotavirus burden significantly reduced in regions with vaccination programs | COVID-19 vaccines demonstrably reduced severe disease and mortality during the pandemic | CDC, WHO, and peer-reviewed literature consistently document these associations

Limitations: Claim uses broad language ('contributed to') which accounts for multiple factors (vaccination, sanitation, antibiotics, healthcare improvements) | Some diseases had pre-vaccine decline due to other factors, though vaccination typically accelerated reduction | Regional variation in vaccine coverage affects outcomes differently across populations | Causation claims require epidemiological interpretation, though evidence is robust

google (gemini-2.5-flash-lite) · supported · 100%

Scientific consensus and extensive historical data confirm that vaccines have been a major factor in significantly decreasing the incidence of numerous infectious diseases worldwide.

Key points: Vaccines work by stimulating the immune system to recognize and fight specific pathogens. | Eradication or near-eradication of diseases like smallpox and polio are direct results of widespread vaccination campaigns. | Reductions in measles, diphtheria, tetanus, and pertussis are also strongly linked to vaccine implementation. | Global health organizations like the WHO and CDC provide comprehensive data and research supporting vaccine efficacy. | The impact of vaccines is evident in mortality and morbidity rates declining dramatically for vaccine-preventable diseases.

Limitations: While vaccines have reduced many diseases, some infectious diseases may still persist or re-emerge due to factors like insufficient vaccination rates or vaccine resistance. | The effectiveness and impact can vary depending on the specific vaccine, the disease it targets, and the population's health and environmental factors.