Evaluation of Long-term Immunological Responses Following Reduced Dose Quadrivalent Human Papillomavirus (HPV) Vaccine Schedules: A Phase II/III Clinical Trial

Detailed Summary

In Fiji, cervical cancer is the second most frequent cancer and the highest cause of cancer mortality in women. In 2008/9, the Ministry of Health in Fiji accepted a donation of 110,000 doses of quadrivalent HPV vaccine, Gardasil® based on the high cervical cancer disease burden. There was enough vaccine to vaccinate all girls aged 9-12 years (30,338 girls) with a three-dose schedule, but not all girls received three doses of the vaccine. This means those girls that received reduced doses may not be fully protected against the HPV genotypes present in the Gardasil®. While HPV vaccines are highly immunogenic and efficacious in the licensed three-dose schedule, there is limited information about the effectiveness of reduced dose schedules in terms of immunogenicity and memory. There is growing evidence from other studies that two doses of HPV vaccine may be sufficient for protection. Reduced schedules would be of benefit in Fiji due to improved costs and logistics. This study will examine whether one or two doses of HPV vaccine provide similar immunological evidence of long-term protection to the standard three-dose schedule in terms of antibody titres to the genotypes present in the Gardasil®. To compare immunological memory responses between dosage groups, a dose of Cervarix ® will be administered to all girls so that the magnitude of the memory responses can be measured.

Study Details

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