Association of Varying Number of Doses of Quadrivalent Human Papillomavirus Vaccine With Incidence of Condyloma

• Published in: JAMA : the journal of the American Medical Association 2014-02, Vol.311 (6), p.597-603
• Main Authors: Herweijer, Eva, Leval, Amy, Ploner, Alexander, Eloranta, Sandra, Simard, Julia Fridman, Dillner, Joakim, Netterlid, Eva, Sparén, Pär, Arnheim-Dahlström, Lisen
• Format: Article
• Language: English
• Subjects: Adolescent; Arbetsmedicin och miljömedicin; Biological and medical sciences; Child; Clinical Medicine; Clinical outcomes; Cohort Studies; Condylomata Acuminata - epidemiology; Condylomata Acuminata - prevention & control; Cost-Benefit Analysis; Dermatologi och venereologi; Dermatology and Venereal Diseases; Drug dosages; Environmental Health and Occupational Health; Female; General aspects; Health Sciences; Human papillomavirus; Human papillomavirus 11; Human papillomavirus 6; Humans; Hälsovetenskap; Incidence; Infectious diseases; Klinisk medicin; Medical and Health Sciences; Medical sciences; Medicin och hälsovetenskap; Papillomavirus Infections - prevention & control; Papillomavirus Vaccines - administration & dosage; Prevention and actions; Public health. Hygiene; Public health. Hygiene-occupational medicine; Registries - statistics & numerical data; Risk assessment; Sweden - epidemiology; Uterine Cervical Neoplasms - prevention & control; Vaccination - statistics & numerical data; Vaccines; Viral diseases; Viral infections; Young Adult
• ISSN: 0098-7484; 1538-3598; 1538-3598
• DOI: 10.1001/jama.2014.95

IMPORTANCE Determining vaccine dose-level protection is essential to minimize program costs and increase mass vaccination program feasibility. Currently, a 3-dose vaccination schedule is recommended for both the quadrivalent and bivalent human papillomavirus (HPV) vaccines. Although the primary goal of HPV vaccination programs is to prevent cervical cancer, condyloma related to HPV types 6 and 11 is also prevented with the quadrivalent vaccine and represents the earliest measurable preventable disease outcome for the HPV vaccine. OBJECTIVE To examine the association between quadrivalent HPV vaccination and first occurrence of condyloma in relation to vaccine dose in a population-based setting. DESIGN, SETTING, AND PARTICIPANTS An open cohort of all females aged 10 to 24 years living in Sweden (n = 1 045 165) was followed up between 2006 and 2010 for HPV vaccination and first occurrence of condyloma using the Swedish nationwide population-based health data registers. MAIN OUTCOMES AND MEASURES Incidence rate ratios (IRRs) and incidence rate differences (IRDs) of condyloma were estimated using Poisson regression with vaccine dose as a time-dependent exposure, adjusting for attained age and parental education, and stratified on age at first vaccination. To account for prevalent infections, models included a buffer period of delayed case counting. RESULTS A total of 20 383 incident cases of condyloma were identified during follow-up, including 322 cases after receipt of at least 1 dose of the vaccine. For individuals aged 10 to 16 years at first vaccination, receipt of 3 doses was associated with an IRR of 0.18 (95% CI, 0.15-0.22) for condyloma, whereas receipt of 2 doses was associated with an IRR of 0.29 (95% CI, 0.21-0.40). One dose was associated with an IRR of 0.31 (95% CI, 0.20-0.49), which corresponds to an IRD of 384 cases (95% CI, 305-464) per 100 000 person-years, compared with no vaccination. The corresponding IRDs for 2 doses were 400 cases (95% CI, 346-454) and for 3 doses, 459 cases (95% CI, 437-482). The number of prevented cases between 3 and 2 doses was 59 (95% CI, 2-117) per 100 000 person-years. CONCLUSIONS AND RELEVANCE Although maximum reduction in condyloma risk was seen after receipt of 3 doses of quadrivalent HPV vaccine, receipt of 2 vaccine doses was also associated with a considerable reduction in condyloma risk. The implications of these findings for the relationship between number of vaccine doses and cervical cancer risk require f