Are vaccines an effective tool to prevent disease?

Vaccines are proven to prevent disease — I'll pull the latest evidence on their effectiveness.

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

Scientific and public health agencies consistently describe vaccination as a highly effective preventive intervention:

> Vaccination is one of the most effective ways to prevent diseases and Vaccination is one of the most effective interventions against infectious diseases and is estimated to prevent 2-3 million deaths annually

> Vaccines are safe, effective and life-saving. Before approval by relevant regulatory agencies, vaccines undergo rigorous clinical trials to test their quality, safety and efficacy

How they work and what they prevent

•Vaccines reduce risks of getting a disease by working with your body's natural defenses to build protection. When you get a vaccine, your immune system responds.

•Vaccines train your immune system to create antibodies, just as it does when it's exposed to a disease. However, because vaccines contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put you at risk of its complications.

We now have vaccines to prevent more than 30 life-threatening diseases and infections, helping people of all ages live longer, healthier lives. These include diseases such as diphtheria, tetanus, pertussis (whooping cough), influenza, measles, cervical cancer, cholera, COVID-19, hepatitis B, polio, rabies and others.

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

Long-term impact:

•Over the past 50 years, essential vaccines against just 14 diseases have saved at least 154 million lives.

•In the United States, research shows that routine vaccinations for children born during 1994–2023 will have prevented about 508 million illnesses and 32 million hospitalizations and saved over 1.1 million lives.

•Vaccines have resulted in the eradication of two major pathogens, rinderpest and smallpox, as well as the local elimination of others, such as measles.

Vaccines are also critical to the prevention and control of infectious disease outbreaks.

Effectiveness vs. perfect protection

Vaccines can stop most people from getting sick, but not everyone. Even after someone receives all of the recommended doses and waits a few weeks for immunity to build up, there is still a chance that they can get infected. Vaccines do not provide full (100%) protection because of many factors, including our individual differences in immunity and response to infection.

Breakthrough infections can occur, but If vaccinated people do get sick, they are likely to have milder symptoms, in general 'It is very rare for someone vaccinated to experience severe illness or die.

Effectiveness can vary by vaccine, disease, variant, time since vaccination, and population coverage. For example, vaccines are proving effective against existing variants, especially at preventing severe disease, hospitalization and death.

Because protection from the initial dose or primary series may weaken over time, booster doses help strengthen and extend protection.

In summary, while no vaccine is 100% effective for every individual and community-level protection depends on coverage, vaccines are proven to be an extremely effective, safe, and cost-effective way to prevent morbidity, mortality, hospitalization and spread of infectious diseases. Talk to your healthcare provider about recommended vaccines for you and your family.

Citations (3)

1who.intGovernment
Vaccine efficacy, effectiveness and protection
Backs: “Vaccination is one of the most effective ways to prevent diseases and Vaccination is one of the most effective interventions against infectious diseases and is estimated to prevent 2-3 million deaths annually. Vaccines are safe, effective and life-saving. Before approval by relevant regulatory agencies, vaccines…”
2who.intGovernment
Vaccines and immunization
Backs: “Vaccines reduce risks of getting a disease by working with your body's natural defenses to build protection.”
3cdc.govGovernment
Vaccines and the Diseases they Prevent
Backs: “Over the past 50 years, essential vaccines against just 14 diseases have saved at least 154 million lives. In the United States, research shows that routine vaccinations for children born during 1994–2023 will have prevented about 508 million illnesses and 32 million hospitalizations and saved over 1.1 million lives.”