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Extended Follow-up of Young Women in Costa Rica Who Received Vaccination Against Human Papillomavirus Types 16 and 18 and Unvaccinated Controls

20 Years
32 Years
Open (Enrolling)
Cervical Neoplasia, HPV Infections

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Trial Information

Extended Follow-up of Young Women in Costa Rica Who Received Vaccination Against Human Papillomavirus Types 16 and 18 and Unvaccinated Controls

Human papillomavirus (HPV) infection is necessary for the development of cervical cancer.
Worldwide, infection with HPV types 16 and 18 account for approximately 70% of cervical
cancer cases. Currently available data suggest that prophylactic vaccination against HPV
types-16 and 18 is nearly 100% effective in preventing persistent cervical infections and
resultant disease from these types for at least five years following vaccination. Intramural
NCI and a group of Costa Rican investigators have had long-time involvement in studies to
elucidate the natural history of HPV and cervical cancer, and in the development of
prophylactic HPV vaccines. In 2004, we initiated a community-based randomized clinical trial
in Costa Rica to evaluate the safety and efficacy of a bivalent virus-like particle
HPV-16/18 vaccine. The study successfully randomized 7,466 women; active follow-up of these
women is underway and is planned for 4 years. Herein, we propose to extend follow-up of
women recruited into this trial and vaccinated with the HPV- 16/18 vaccine at the start of
CVT for up to an additional 6 years, for a total of up to 10 years of follow-up. We expect
to provide the HPV-16/18 vaccine to women in the control arm of the trial after the initial
4 years of follow-up are completed, and propose to follow them for an additional 2 years, to
monitor vaccine safety and to maximize detection of persistent infections and lesions
resultant from HPV exposure that occurred before cross-over to the HPV vaccination (a subset
of these women will be followed for the entire 10 years). We will also enroll and follow a
new group of approximately 3000 women who will be followed with state-of-the-art screening
and will serve as an unvaccinated control group (UCG) during the extended follow-up period.
Women will be screened at two year intervals. Women with evidence of cervical abnormalities
will have accelerated screening and will be referred to colposcopy for evaluation and
treatment if needed. Questionnaires and biological specimens collected during this follow-up
period will allow for many unique scientific and women's health questions to be addressed.

There are three overarching objectives for this effort. They are as follows:

1. To evaluate the 1 O-year global impact of HPV-16/18 vaccination of young adult women;

2. To evaluate determinants of the immune response to HPV and the vaccine, and markers of
long-term protection; and,

3. To evaluate the natural history of HPV and cervical disease in vaccinated and
unvaccinated populations.

This research will provide invaluable data that will allow for the continued investigation
into the risks and benefits of the prophylactic HPV vaccine.

Inclusion Criteria


- Gender: Female

- Age: Women born in or between July 1978 and November 1987

- Residence: Residents of Guancaste Province and a few areas of Puntarenas closest to
Guanacaste at some point during 2005

- Language: Able to speak/understand Spanish

- Mental Competence: Apparently mentally competent

- Consent: Written informed consent obtained prior to enrollment


The following criteria will be checked at the time of enrollment for potential
participants of the unvaccinated control group. If any apply, the participant will not be
included in the study.

- History of cervical cancer,

- History of hysterectomy,

- Any important medical condition or other criteria that the investigator considers
that precludes enrollment,

- Vaccination with Gardasil or cervarix will be an exclusionary criterion, but few
women are expect ed to have received these vaccines at the time of enrollment. Use of
these vaccines after enrollment is not a criteria for study interruption but we plan
to collect information on vaccination history so that the few women who report having
been vaccinated with one of the HPV vaccines after enrollment can be evaluated
separately at analysis.

Type of Study:


Study Design:


Outcome Measure:

Infection with cervical, oral, vulvar and anal HPV, development of cervical neoplasia

Principal Investigator

Allan Hildesheim, Ph.D.

Investigator Role:

Principal Investigator

Investigator Affiliation:

National Cancer Institute (NCI)


United States: Federal Government

Study ID:




Start Date:

March 2009

Completion Date:

Related Keywords:

  • Cervical Neoplasia
  • HPV Infections
  • Human Papillomavirus
  • Vaccine
  • Natural History
  • Cervix
  • Immune Response
  • HPV
  • Neoplasms



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