Evidence for single-dose protection by the bivalent HPV vaccine—Review of the Costa Rica HPV vaccine trial and future research studies

• Published in: Vaccine Vol. 36; no. 32; pp. 4774 - 4782
• Main Authors: Kreimer, Aimée R., Herrero, Rolando, Sampson, Joshua N., Porras, Carolina, Lowy, Douglas R., Schiller, John T., Schiffman, Mark, Rodriguez, Ana Cecilia, Chanock, Stephen, Jimenez, Silvia, Schussler, John, Gail, Mitchell H., Safaeian, Mahboobeh, Kemp, Troy J., Cortes, Bernal, Pinto, Ligia A., Hildesheim, Allan, Gonzalez, Paula
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 06.08.2018; Elsevier Limited; Elsevier Science
• Subjects: Adolescent; Adult; Allergy and Immunology; antibodies; Antibodies, Viral - immunology; Antibody response; Cervical cancer; Clinical trials; Clinical Trials as Topic; Costa Rica; Costa Rica - epidemiology; Deoxyribonucleic acid; DNA; Durability; experimental design; Female; HPV; HPV-driven cancers; Human papillomavirus; Human papillomavirus 16 - immunology; Human papillomavirus 18 - immunology; Humans; Immunization Schedule; Laboratories; Mass Vaccination; Medical screening; Papillomavirus Infections - epidemiology; Papillomavirus Infections - prevention & control; Papillomavirus Infections - therapy; Papillomavirus Vaccines - administration & dosage; Papillomavirus Vaccines - therapeutic use; Prevention; Reduced dose; Serum - immunology; Studies; Time Factors; Uterine Cervical Neoplasms - epidemiology; Uterine Cervical Neoplasms - prevention & control; Uterine Cervical Neoplasms - therapy; Vaccination; Vaccine; Vaccines; women; Womens health; United States > US; Costa Rica; Prevention; Human papillomavirus; HPV-driven cancers; Reduced dose; Vaccine; Cervical cancer; HPV
• ISSN: 0264-410X; 1873-2518; 1873-2518
• DOI: 10.1016/j.vaccine.2017.12.078

The Costa Rica Vaccine Trial (CVT), a phase III randomized clinical trial, provided the initial data that one dose of the HPV vaccine could provide durable protection against HPV infection. Although the study design was to administer all participants three doses of HPV or control vaccine, 20% of women did not receive the three-dose regimens, mostly due to involuntary reasons unrelated to vaccination. In 2011, we reported that a single dose of the bivalent HPV vaccine could be as efficacious as three doses of the vaccine using the endpoint of persistent HPV infection accumulated over the first four years of the trial; findings independently confirmed in the GSK-sponsored PATRICIA trial. Antibody levels after one dose, although lower than levels elicited by three doses, were 9-times higher than levels elicited by natural infection. Importantly, levels remained essentially constant over at least seven years, suggesting that the observed protection provided by a single dose might be durable. Much work has been done to assure these non-randomized findings are valid. Yet, the group of recipients who received one dose of the bivalent HPV vaccine in the CVT and PATRICIA trials was small and not randomly selected nor blinded to the number of doses received. The next phase of research is to conduct a formal randomized, controlled trial to evaluate the protection afforded by a single dose of HPV vaccine. Complementary studies are in progress to bridge our findings to other populations, and to further document the long-term durability of antibody response following a single dose.