4 research outputs found
Rationale and design of a community-based double-blind randomized clinical trial of an HPV 16 and 18 vaccine in Guanacaste, Costa Rica
We report the rationale, design, methods and details of participation of a community-based, double-blind,
randomized clinical trial of an HPV 16 and 18 vaccine conducted in two provinces of Costa Rica to investigate the efficacy and population impact of the vaccine in the prevention of cervical cancer precursors.
More than 24,000 women between 18 and 25 years of age were invited to participate and pre-screened for
eligibility, with recruitment of 7466 women (30% of those pre-screened, 59% of those eligible) who were
randomized to receive 3 doses of the HPV vaccine or hepatitis A vaccine as control. A complex protocol of
data and specimen collection was applied, including an interview, pelvic exam for sexually active women,
blood for serology and cell-mediated immunity, cervical secretions for local immunity and cells for HPV,
Chlamydia trachomatis and gonorrhea testing. Eighty percent of the women received three doses, 12.4%
two doses and 7.4% one dose. At visits, compliance with data and specimen collection was close to 100%.
Baseline characteristics and age-specific prevalence of HPV and cervical neoplasia are reported. Overall
prevalence of HPV was high (50%), with 8.3% of women having HPV 16 and 3.2% HPV 18. LSIL was detected
in 12.7% of women at baseline and HSIL in 1.9%. Prevalence of Chlamydia was 14.2%. There was very good
agreement in HPV detection between clinician-collected and self- collected specimens (89.4% agreement
for all types, kappa 0.59). Follow up will continue with yearly or more frequent examinations for at least
4 years for each participant.Office for Research on Women’s Health/[]/NIH/Estados UnidosNational Cancer Institute/[N01-CP-11005]/NCI/Estados UnidosFood and Drug Administration/[BB-IND 7920]/FDA/Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC