Why are vaccines needed if the diseases they prevent are not as common anymore?”
Vaccines are still needed because the bacteria and viruses that cause these diseases still exist. Vaccines have protected children and continue to protect children from getting these diseases. In the United States many diseases are not as common or widespread as they used to be thanks to better nutrition, less crowded living conditions, better sanitation, antibiotics, and, most importantly, vaccines. Vaccines also are needed to protect children from diseases that may be brought into the United States from people who have visited or are visiting from other countries. Many vaccine-preventable diseases are still common in many parts of the world. Travelers may be carriers of these diseases without them knowing they are infected. Influenza is an example of a disease that is transmitted between countries every year.
