Why are there so many vaccines?
A: Currently, the U.S. childhood vaccination schedule for children between birth and six years of age recommends immunizations for 14 different diseases. Most of those disease are rare; however, they can cause serious illness or death in unvaccinated populations. If we stop vaccinating for those diseases, the diseases could quickly reappear again. In recent years, the United States has seen an uptick in measles outbreaks because vaccination rates have dropped. Before vaccinations were introduced, measles infected 4 million children, killing 3,000, and polio paralyzed about 10,000 children annually.