Vaccine History and Success

Vaccine history and success

High vaccination rates in people and pets in the United States, Canada and Europe have helped prevent many infectious diseases and have resulted in less sickness and millions of lives saved.

In the United States, vaccinations required by law before a child can enter school have resulted in record-low incidence levels of vaccine-preventable diseases. The only vaccine required by law for dogs and cats is rabies, and although the disease has not been eradicated worldwide, it is now rarely seen in U.S. pets or people.

Human disease cases

Vaccination success is evident when you look at reliable data from the Centers for Disease Control and Prevention (CDC) that shows how many cases of vaccine-preventable diseases there were each year before and after the introduction of vaccines.

Even with this remarkable success, it’s important to remember that all of these diseases, except smallpox, are still found in areas of the world and are still a threat to any unvaccinated person, even in the U.S.  We have seen whooping cough and measles outbreaks with peaks every three to five years, particularly in areas where vaccination rates are declining.

Pet disease cases

Although there is no reporting entity for pet diseases like the CDC, we know diseases such as parvo and distemper are rarely seen in U.S. vaccinated pets. However, unvaccinated pets are at risk because potentially dangerous diseases are still around.

Shelters still experience outbreaks of parvovirus and distemper in dogs, and calicivirus and panleukopenia in cats. Because of the constant movement of pet populations where pets are moving from a shelter to a home or a home to a shelter, from a breeder to a home, from one home to another, from one state to another, these diseases and others can easily spread to unvaccinated pets in the general population.

Unvaccinated pets are susceptible to infectious agents shed by unvaccinated pets at the dog park, at the groomers, during boarding, on a neighborhood walk or even in backyards. Pet owners need to be aware of these potential exposures and be advised to vaccinate their pets against dog and cat diseases that are still prevalent wherever their pets go.

To keep pets healthy, be sure to discuss vaccinations with your veterinarian at every annual wellness exam.

How important it is to vaccinate your pet.


The prevalence of dog and cat diseases in shelters.


Many diseases are still prevalent in some areas of the world that do not have access to clean water or vaccinations. All unvaccinated U.S. citizens who travel internationally are at risk of coming in contact with vaccine-preventable diseases, as well as bringing these diseases back home and infecting other unvaccinated people.


The public’s faith in the value of vaccines was at an all time high in 1955 with the introduction of the Salk polio vaccine, resulting in the total eradication of polio in the U.S. less than 50 years later.

Source: Roush, SW, et al. JAVMA (298) 2007, 2155.