A new study shows that the vaccine against the types of human papillomavirus—or HPV—that commonly cause cervical cancer in women has dropped by half since the vaccine was introduced in 2006.
The study, published last month in the Journal of Infectious Diseases, looked at the prevalence of HPV infections in girls and women before and after the vaccine’s introduction. It found that after the vaccine was rolled out, the prevalence of the HPV strain that is targeted by the vaccine dropped 56 percent among women ages 14 to 19.
The development of a vaccine prompted some states to require it for school admission, but an initial flurry of activity has died down, according to the National Conference of State Legislatures.