How Were Results from the HPV Vaccine Studies Analyzed?
The vaccine studies were analyzed in several different ways. One analysis looked only at girls whose pre-vaccine testing did not show any evidence of current or past infection with the HPV types that are in the vaccine. In people who did not already have one of the four types of HPV, the vaccine was 91 – 100% effective in preventing pre-cancers that were associated with the four vaccine HPV types. They still got pre-cancer associated with non-vaccine HPV types at the same rate as un-vaccinated girls. The only way to know if you are going to get this response is if you have never had sex before the vaccine, or you have been tested for evidence of prior infection. The HPV test is recommended by the American Cancer Society as part of cancer screening every three years in women older than 30, but it is not yet widely covered by insurance plans outside of these recommendations. The more useful analysis was called the general population. This is all study participants analyzed together, with
