Are vaccines an effective tool to prevent disease?

Vaccines prevent disease — I'll gather the latest evidence on how well they work.

Yes, vaccines are one of the most effective tools to prevent disease - this is supported by extensive scientific evidence and public health data.

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

> Vaccines are among the most powerful inventions in history, making once-feared diseases preventable

1. Lives saved and deaths prevented

Of the vaccines included in the 50-year study, the measles vaccination had the most significant impact on reducing infant mortality, accounting for 60% of the lives saved due to immunization.

Vaccination has also directly contributed to reducing infant deaths by 40% globally, and by more than 50% in the African Region.

2. Eradication and control of diseases

> Immunization is among the most successful and cost-effective public health interventions. Immunization programs have led to eradication of smallpox, elimination of measles and poliomyelitis in regions of the world, and substantial reductions in the morbidity and mortality attributed to diphtheria, tetanus, and pertussis

Historically, the introduction of a vaccine has, in many cases, led to a very large decrease in the incidence of the targeted disease — such as the 96% decrease in the incidence of polio that occurred within 7 years of the introduction of the Salk and Sabin polio vaccines

3. Effectiveness against infection and severe outcomes

Vaccines provide cost-effective, long-term protection and are highly effective, though not 100%:

> Based on what we know so far, vaccines are proving effective against existing variants, especially at preventing severe disease, hospitalization and death

Vaccines work by training the immune system to recognize pathogens, reducing incidence, transmission, complications, and the need for drug treatments that can drive antimicrobial resistance. Like all medical interventions, vaccines are rigorously tested in multiple phases of clinical trials and continuously monitored for safety and efficacy at local, national, and global levels.

In summary, the scientific consensus from WHO, CDC, UNICEF and peer-reviewed research is that vaccines are safe, cost-effective, and highly effective at preventing infectious diseases, reducing deaths and disability, and have already eradicated or nearly eradicated several major diseases.