5.5 million people in the United States are infected every year with Human Papilloma Virus (HPV). Researchers want to know if the vaccine has actually decreased the number of people infected. A recent study is believed to be the first to show a substantial decrease in HPV infection in a community setting as well as herd protection. Herd protection meaning a decrease in infection rates among unimmunized individuals that occurs when a critical mass of people in a community is immunized against a contagious disease.
