What is LTFU Study?
The LTFU Study is a prolonged 6-year evaluation to determine the protection of vaccines against infections caused by HPV 16/18 that included a group of women participating in the CVT VACCINATION STUDY (Phase III Efficacy Study of an HPV16/18 vaccine), who were vaccinated and completed the initial 4-year follow-up. This study was designed to determine the long-term efficacy of the HPV vaccine, therefore, nearly 6,000 vaccinated and unvaccinated women, residents of the province of Guanacaste, Costa Rica and nearby areas participated voluntarily.
The LTFU Study means:
Prolonged follow-up of young, healthy women in Costa Rica vaccinated and not vaccinated against the Human Papillomavirus.
Importance of the LTFU Study
This research study answers the question: What is the global impact on cervical pre-cancer and cancer rates over a 10-year period of vaccinating young adult women against HPV?
The importance of this long-term evaluation comes from the first 4 years of follow-up of the CVT VACCINATION STUDY, which made it possible to evaluate the short-term impact of vaccination in relation to the presence of CIN3+ (severe cervical intraepithelial neoplasia, cancer in situ or invasive cervical cancer), so data on the protective effect of the vaccine beyond the first 4 years were required.
A formal evaluation of the impact of the vaccine over a period of 10 years would take the participating population of the CVT who agreed to continue their participation in the LTFU Study, up to the age of 28 to 35 years, thus covering the period of more high risk of CIN3+. In this way, the 10-year evaluation would provide a better estimate of the impact of vaccination “throughout life”, since most CIN3+ events occur at the age of 35 years in screened populations, therefore , if the evidence for the impact of vaccination at 10 years is high it would suggest that vaccination of young adult women would be justified and the estimates of the impact of vaccination at 10 years obtained in the LTFU would provide key information that could be used by economists in health to model the cost-effectiveness of vaccination programs.
Women who received less than 3 doses of HPV vaccine are of particular interest, as there is information from the CVT Study suggesting that 2 doses and up to 1 dose of vaccine may be sufficient to protect against HPV 16/18 infections.
Objectives of the LTFU Study
- Evaluate the 10-year global impact of vaccinating young adult women against HPV 16/18.
- Evaluate the determinants of the immune response to HPV and the vaccine and the markers of long-term protection.
- Evaluate the natural history of HPV infection and cervical disease in vaccinated and unvaccinated populations.
LTFU Study Design
The LTFU Study proposes a protocol for the 6-year extension of the follow-up period of some of the participants who were vaccinated against HPV 16/18 at the beginning of the CVT VACCINATION STUDY, who would have completed 4 years of participation, for a total of 10 years of active follow-up, with biannual visits, which will allow documenting relevant information on the risk factors and benefits of the prophylactic HPV vaccine.
This study included the participation of 6000 vaccinated and unvaccinated women, residents of the province of Guanacaste, Costa Rica and nearby areas.
Principal Investigator of the LTFU Study: Dr. Paula Gonzalez (RIP), currently the principal investigator is Dr. Carolina Porras and Aimée R. Kreimer Ph.D, NCI
Sponsor: National Cancer Institute of US (NCI).
Institutions participating in the ESCUDDO Project: National Cancer Institute of US (NCI); Costa Rican Agency for Biomedical Research (ACIB-FUNIN), formerly the Guanacaste Epidemiological Project (PEG).
Approved by the Scientific Ethics Committee: CEC- ICIC
