Are vaccines an effective tool to prevent disease?

I'll search for current evidence on how well vaccines prevent disease.

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

Scientific consensus and historical evidence support this:

> Vaccination is one of the most effective ways to prevent diseases. Over the past 50 years, essential vaccines against just 14 diseases have saved at least 154 million lives (1).

> Immunization currently prevents 3.5 million to 5 million deaths every year from diseases like diphtheria, tetanus, pertussis (whooping cough), influenza and measles.

> Immunization is a global health success story, saving millions of lives every year. Vaccines reduce risks of getting a disease by working with your body’s natural defenses to build protection.

Other estimates:
> Vaccination is one of the most effective interventions against infectious diseases and is estimated to prevent 2-3 million deaths annually
> have resulted in the eradication of two major pathogens, rinderpest and smallpox, as well as the local elimination of others, such as measles

Historical impact in the United States and worldwide

> Through vaccination, endemic smallpox has been eradicated worldwide, poliomyelitis has been eliminated in the Western hemisphere, and diseases such as measles, rubella, tetanus, diphtheria and Hib, once responsible for significant morbidity and mortality in the US and other parts of the world, have been controlled.

JAMA study comparing pre-vaccine baselines to recent data:

> A greater than 92% decline in cases and a 99% or greater decline in deaths due to diseases prevented by vaccines recommended before 1980 were shown for diphtheria, mumps, pertussis, and tetanus.
> Endemic transmission of poliovirus and measles and rubella viruses has been eliminated in the United States; smallpox has been eradicated worldwide.

> The number of cases of most vaccine-preventable diseases is at an all-time low; hospitalizations and deaths have also shown striking decreases.

> Vaccines are among the greatest achievements of biomedical science and public health

Specific vaccine effectiveness

> Measles: one dose of vaccine was 95% effective in preventing measles.

> We now have vaccines to prevent more than 30 life-threatening diseases and infections, helping people of all ages live longer, healthier lives.

Vaccines are also described as reasonably effective in limiting spread and containing severe disease progression, and are critical to the prevention and control of infectious disease outbreaks.

Effectiveness depends on the vaccine, pathogen, variant, and vaccination coverage and maintenance of herd immunity, but overall evidence shows vaccines are a highly effective, safe, and cost-effective public health intervention.