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HPV Vaccine Trial in Costa Rica (CVT)

The HPV Vaccine Trial in Costa Rica (CVT) is a collaboration between investigators in Costa Rica and the National Cancer Institute. The trial was designed as a blinded, randomized, phase III clinical trial to evaluate the efficacy of a bivalent HPV-16/18 virus-like particle (VLP) vaccine. The vaccine used in the trial was developed by investigators at NCI and other research institutions and is manufactured by GlaxoSmithKline Biologicals. The trial was initiated in June 2004 and enrollment was completed in December 2005; there were 7,466 women enrolled. 

Trial staff followed all enrolled women for a period of four years. Women who were eligible, consented, and were randomized into the trial received three doses of the HPV 16/18 VLP or Havrix (Hepatitis A) vaccine over a period of six months. At entry and throughout follow-up, women were carefully monitored and received state-of-the-art screening for cervical neoplasia. 

This study was designed to evaluate vaccine efficacy, immunological correlates of long-term vaccine success and failure, and other factors of immunological and etiological interest. Data from the trial demonstrated that three doses of the HPV vaccine may not be necessary, as similar vaccine efficacy against cervical HPV 16/18 infection was observed among women who received two, and even a single dose, of the HPV vaccine after four years of follow-up.

For more information, contact Aimée Kreimer.

Infections and Immunoepidemiology Branch - Research Areas