1796: Edward Jenner develops the smallpox vaccine, marking the first successful vaccination.
1801: The smallpox vaccine is introduced in the United States.
1853: Massachusetts becomes the first state to require smallpox vaccination for schoolchildren.
1890s: Vaccines for diphtheria, tetanus, and pertussis are developed.
1905: The Supreme Court upholds the constitutionality of state vaccination mandates.
1920s: Vaccines for measles, mumps, and rubella are introduced.
1930s: The American Academy of Pediatrics recommends a schedule of childhood vaccinations.
1960s: Vaccines for polio, chickenpox, and hepatitis B are developed.
1970s: Vaccines for Haemophilus influenzae type b (Hib) and rotavirus are introduced.
1980s: Vaccines for pneumococcal disease and human papillomavirus (HPV) are developed.
1990s: Vaccines for meningococcal disease and varicella are introduced.
2000s: Vaccines for influenza B and COVID-19 are developed.

now for diseases vaccines prevented

Several infectious diseases have been successfully eradicated or significantly reduced through widespread vaccination programs, including:

Smallpox:
The first disease to be globally eradicated, smallpox was eliminated in 1980.

Tetanus:
Nearly eradicated in many parts of the world, tetanus is now primarily found in developing countries.

Measles:
Eliminated in the United States in 2000, measles cases have been significantly reduced globally.

Pertussis (whooping cough):
Once a major cause of childhood deaths, pertussis has been largely controlled by vaccination.

Rubella:
Eliminated in the United States and many other countries, rubella is a serious threat to pregnant women.

Diphtheria:
A bacterial infection that can cause severe respiratory problems, diphtheria has been largely eradicated in developed countries.

Polio:
Two of the three types of poliovirus have been eradicated globally, and the remaining type is on the verge of eradication.

Rabies:
Eradicated in several countries, rabies can be prevented through vaccination of pets and livestock.