I've heard that vaccines are not needed because these diseases were disappearing even before the vaccines were developed.
Vaccines are still very important. Thanks to better nutrition, less crowded living conditions, antibiotics, and, most importantly, vaccines, many diseases do not occur or spread as much as they used to, but the bacteria and viruses that are responsible for these diseases remain in our environment. Immunizations are still needed to protect children from these diseases.
For example, Haemophilus influenzae type b (Hib) diseases were a major problem a few years ago until the vaccine was developed for infants. Over several years, we went from 20,000 cases of Hib diseases to less than a few hundred. The vaccine is the only explanation for this decrease. Unvaccinated children are still at risk for Hib meningitis and other serious illnesses.
These diseases have been virtually eliminated from the United States. Does my child need to be vaccinated?
Immunizations have reduced most of these diseases to very low levels in the United States. However, some of these diseases are still common in other parts of the world. Travelers can bring these diseases into this country. Without immunizations, these infections could quickly spread here. Immunizations also help people who cannot be vaccinated or who do not respond to vaccines if those around them are vaccinated.