Are vaccines an effective tool to prevent disease?

I'll gather the latest evidence on vaccine effectiveness to answer your question.

Yes, vaccines are one of the most effective tools to prevent disease.

Scientific and public health consensus is that:

> Vaccination is one of the most effective ways to prevent diseases.

Evidence of Effectiveness

Large-scale lives saved:

•Over the past 50 years, essential vaccines against just 14 diseases have saved at least 154 million lives. The WHO also reports vaccines have saved more than 150 million lives as people chose to protect themselves from diseases like measles, diphtheria, pertussis, polio, and rotavirus.

•According to the WHO, vaccination prevents an estimated 2-3 million deaths every year. Other WHO estimates cited are that immunization prevents between 3.5 million and 5 million deaths each year from diseases such as diphtheria, tetanus, pertussis, influenza, and measles.

Historic eradication and control:

•Vaccines have been instrumental in controlling and eliminating many serious diseases, such as smallpox, polio, and measles.

•Thanks to a global vaccination campaign led by the WHO, smallpox was eradicated in 1980. Smallpox, a deadly disease that killed millions, was eradicated globally in 1980 following a successful vaccination campaign.

•Polio, once a feared disease causing paralysis and death, has been nearly eradicated worldwide thanks to the polio vaccine.

High efficacy for specific vaccines:

•The measles vaccine is about 97% effective after two doses, drastically reducing the incidence of measles outbreaks. Similarly, the effectiveness of the MMR vaccine is 97% after 2 doses.

•According to the Centers for Disease Control and Prevention (CDC), overall varicella vaccine effectiveness is 82% after 1 dose and 92 to 98% after 2 doses; effectiveness against severe varicella is 100% after even 1 dose.

•HPV vaccines reduce the risk of cervical cancer by 80% in women vaccinated by age 16 years and 66% in those vaccinated after 16. The review concludes that HPV vaccines continue to offer substantial public health benefits, with strong evidence supporting their role in preventing cancer and precancerous disease.

•A sweeping global review led by researchers at the University of British Columbia has found that mRNA vaccines—now administered billions of times worldwide—are safe and highly effective at preventing infectious diseases like COVID-19.

•For influenza, for the 2024–2025 flu season, the CDC estimated that flu vaccination prevented about 10 million flu-related illnesses in the U.S., 5 million medical visits, 185,000 hospitalizations and 12,000 deaths.

•One EuroSAVE study found that an up-to-date COVID-19 vaccine received within the past six months was 72 per cent effective at preventing hospitalization and 67 per cent effective at preventing the most serious outcomes, including ICU admission and death.

How vaccines prevent disease

Vaccines have been proven to be highly effective in preventing infectious diseases. By introducing a small, harmless piece of a pathogen to the body, vaccines stimulate the immune system to produce antibodies that can recognize and fight the disease-causing agent.

When enough people are immunized, it creates herd immunity - when enough people are immune to an infectious disease to slow or prevent transmission, protecting those who cannot be vaccinated. The threshold for herd immunity is generally considered to be around 80-95% of the population.

Vaccines cannot always prevent infection, but they can substantially reduce the risk of serious disease.

Like any medicine, vaccines can cause side effects, however, these are usually very minor and of short duration, such as a sore arm or a mild fever. More serious side effects are possible but extremely rare. A person is far more likely to be seriously harmed by a disease than by a vaccine.

This information is for educational purposes and not medical advice. Consult a healthcare provider for personal medical decisions.

Citations (3)

1who.intGovernment
Vaccines and immunization: Vaccine safety
Backs: “Yes, vaccines are one of the most effective tools to prevent disease. Scientific and public health consensus is that:”
2un.orgGovernment
For every generation, vaccines work and they have saved over 150 million lives: WHO
Backs: “Over the past 50 years, essential vaccines against just 14 diseases have saved at least 154 million lives. The WHO also reports vaccines have saved more than 150 million lives as people chose to protect themselves from diseases like measles, diphtheria, pertussis, polio, and rotavirus.”
3numberanalytics.comNot yet classified
Vaccination: A Public Health Imperative
Backs: “The WHO also reports vaccines have saved more than 150 million lives as people chose to protect themselves from diseases like measles, diphtheria, pertussis, polio, and rotavirus. According to the WHO, vaccination prevents an estimated 2-3 million deaths every year.”