Effector and Memory Immune Responses to HPV Vaccination in Vietnamese Women Post Virus Exposure

Inclusion Criteria: * Is between the reporting ages of 18-26 years at the time of recruitment. * Engage in commercial sex in the last 6m (for FSW group) or have engaged in sexual activity (non-FSWs) * Willing and able to give written informed consent. * Willing to complete the follow-up requirements of the study. Exclusion criteria Participants meeting any of the following criteria will be excluded from the trial: * Pregnant or possibly pregnant * Has received any HPV vaccine previously * Has an axillary temperate greater than 38°C * Known allergies to any vaccine component * incapacity to provide consent * Currently receiving immunosuppressive medication or anti-cancer chemotherapy. * Known HIV infection. * Known Congenital immune deficiency syndrome.