This objective of this contract is to support a new trial aimed at evaluating the non-inferiority of 1 versus 2 doses of the HPV vaccines and an additional extension to the follow-up of women in NCI?s ongoing Costa Rica Vaccine Trial (CVT) (which initially followed women for 10 years and will now extend that follow up out to 15 years among a subset of participants). CVT showed similar HPV vaccine efficacy over four years among women who received one, two and three doses of the HPV16/18 vaccine, and stable antibody responses have been observed throughout the seven years of follow-up accrued to date in CVT. Following up on these discoveries and further documenting the protection afforded by fewer doses could result in a monumental, global public health breakthrough.
