Should we give vaccines to people who are already infected with HPV?

Although the preventive vaccines currently under study have been found to be generally safe when given to women who are already infected with HPV, it is important for women to know that the vaccines protect against infection, and provide maximum benefit, for a woman who is vaccinated before she is sexually active. This is because these vaccines do not treat infections. For example, one recent study found that Cervarix was not effective in helping women who are already infected to clear the infection. However, because very few young women have been infected with all HPV types that are included in the vaccines, it is possible that women may still get residual benefit from vaccination even if they have been infected with one or more of the types included in the vaccines. This possibility has not yet been formally studied.

It is not feasible to prescreen all women to see who has been exposed to the HPV types in the vaccines. At present, there is no generally available test to tell whether an individual has been exposed to HPV. The currently approved HPV DNA test shows only whether a woman has a current HPV infection and identifies the HPV type. It does not provide information on past infections. The decision to vaccinate or not, based on likelihood of prior exposure to these HPV types, is being discussed by ACIP and other advisory groups.

This answer is based on source information from the National Cancer Institute.