Vaccine 26 (2008) 6844–6851 Contents lists available at ScienceDirect Vaccine journal homepage: www.elsevier.com/locate/vaccine HPV antibody levels and clinical efficacy following administration of a prophylactic quadrivalent HPV vaccine Elmar A. Joura a,∗ , Susanne K. Kjaer b , Cosette M. Wheeler c , Kristján Sigurdsson d , Ole-Erik Iversen e , Mauricio Hernandez-Avila f , Gonzalo Perez g , Darron R. Brown h , Laura A. Koutsky i , Eng Hseon Tay j , Patricia García k , Kevin A. Ault l , Suzanne M. Garland m , Sepp Leodolter a , Sven-Eric Olsson n , Grace W.K. Tang o , Daron G. Ferris p , Jorma Paavonen q , Matti Lehtinen r , Marc Steben s , Xavier Bosch t , Joakim Dillner u , Robert J. Kurman v , Slawomir Majewski w , Nubia Mu ˜ noz x , Evan R. Myers y , Luisa L. Villa z , Frank J. Taddeo A , Christine Roberts A , Amha Tadesse A , Janine Bryan A , Lisa C. Lupinacci A , Katherine E.D. Giacoletti A , Shuang Lu A , Scott Vuocolo A , Teresa M. Hesley A , Richard M. Haupt A , Eliav Barr A a Department of Gynecology and Obstetrics, Medical University of Vienna, Vienna, Austria b Department of Virus, Hormones and Cancer, Institute of Cancer Epidemiology, Danish Cancer Society/Rigshospitalet, Copenhagen, Denmark c Departments of Molecular Genetics and Microbiology and Obstetrics and Gynecology, University of New Mexico, Albuquerque, NM, USA d National Cancer Detection Clinic, Reykjavik, Iceland e Department of Clinical Medicine, University of Bergen and Department of Obstetrics and Gynecology, Haukeland University Hospital, Bergen, Norway f Institute of Public Health, Cuernavaca, Morelos, Mexico g Universidad del Rosario, Bogotá, Colombia h Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA i Department of Epidemiology, University of Washington, Seattle, WA, USA j KK Women’s & Children’s Hospital, Singapore k Epidemiology HIV and STD Unit, Universidad Peruana Cayetano Heredia, Lima, Peru l Department of Gynecology and Obstetrics, Emory University School of Medicine, Atlanta, GA, USA m Microbiology and Infectious Diseases Department, Royal Women’s Hospital and Department of Obstetrics and Gynecology, University of Melbourne, Melbourne, Victoria, Australia n Karolinska Institute at Danderyd Hospital, Stockholm, Sweden o Department of Obstetrics and Gynecology, University of Hong Kong, Hong Kong, China p Department of Family Medicine and Obstetrics and Gynecology, Medical College of Georgia, Augusta, GA, USA q Department of Obstetric and Gynecology, University Central Hospital, Helsinki, Finland r School of Public Health, University of Tampere, Tampere, Finland s Direction Risques Biologiques, Environnementaux et Occupationnels, Institut National de Santé Publique du Québec, Montréal, Qc, Canada t Institut Catala d’Oncologia, IDIBELL, Barcelona, Spain u Dept. of Medical Microbiology, Lund University, Sweden v Departments of Gynecology and Obstetrics, Pathology and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA w Department of Dermatology and Venereology, Center of Diagnostics and Treatment of Sexually Transmitted Diseases, Warsaw Medical University, Warsaw, Poland x National Institute of Cancer, Bogotá, Colombia y Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC, USA z Department of Virology, Ludwig Institute for Cancer Research, Sao Paulo, Brazil A Merck Research Laboratories, West Point, PA, USA article info Article history: Received 9 July 2008 Received in revised form 4 September 2008 Accepted 26 September 2008 Available online 16 October 2008 Keywords: Human Papillomavirus Humoral immunity Immune memory abstract The efficacy of the quadrivalent Human Papillomavirus (HPV) vaccine is thought to be mediated by humoral immunity. We evaluated the correlation between quadrivalent HPV vaccine-induced serum anti- HPV responses and efficacy. 17,622 women were vaccinated at day 1, and months 2 and 6. At day 1 and at 6–12 months intervals for up to 48 months, subjects underwent Papanicolaou and genital HPV testing. No immune correlate of protection could be found due to low number of cases. Although 40% of vaccine sub- jects were anti-HPV 18 seronegative at end-of-study, efficacy against HPV 18-related disease remained high (98.4%; 95% CI: 90.5–100.0) despite high attack rates in the placebo group. These results suggest vaccine-induced protection via immune memory, or lower than detectable HPV 18 antibody titers. © 2008 Elsevier Ltd. All rights reserved. ∗ Corresponding author at: Medical University of Vienna, AKH, Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, Währinger Gürtel 18-20, A-1090 Vienna, Austria. Tel.: +43 1 40400 2915; fax: +43 1 40400 2962. E-mail address: elmar.joura@meduniwien.ac.at (E.A. Joura). 0264-410X/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.vaccine.2008.09.073 FOR HKMA CME MEMBER USE ONLY. DO NOT REPRODUCE OR DISTRIBUTE. FOR HKMA CME MEMBER USE ONLY. DO NOT REPRODUCE OR DISTRIBUTE.