Timing of two versus three doses of quadrivalent HPV vaccine and associated effectiveness against condyloma in Sweden: a nationwide cohort study.

OBJECTIVE: To assess incidence of condyloma after two doses of quadrivalent human papillomavirus (qHPV) vaccine, by time since first vaccine dose, in girls and women initiating vaccination before age 20 years. DESIGN: Register-based nationwide open cohort study. SETTING: Sweden. PARTICIPANTS: Girls and women initiating qHPV vaccination before age 20 years between 2006 and 2012. The study cohort included 264 498 girls, of whom 72 042 had received two doses of qHPV vaccine and 185 456 had received all three doses. MAIN OUTCOME MEASURE: Incidence rate ratios (IRRs) of condyloma estimated by time between first and second doses of qHPV in months (m) and age at vaccination, adjusted for attained age. RESULTS: For girls first vaccinated with two doses before the age of 17 years, the IRR of condyloma for 0-3 months between the first and second doses was 1.96 (95% CI 1.43 to 2.68) as compared with the standard three-dose schedule. The IRRs were 1.27 (95% CI 0.63 to 2.58) and 4.36 (95% CI 2.05 to 9.28) after receipt of two doses with 4-7 months and 8+ months between doses, respectively. For women first vaccinated after the age of 17 years, vaccination with two doses of qHPV vaccine and 0-3 months between doses was associated with an IRR of 2.12 (95% CI 1.62 to 2.77). For an interval of 4-7 months between doses, the IRR did not statistically significantly differ to the standard three-dose schedule (IRR=0.81, 95% CI 0.36 to 1.84). For women with 8+ months between dose 1 and dose 2 the IRR was 3.16 (95% CI 1.40 to 7.14). CONCLUSION: A two-dose schedule for qHPV vaccine with 4-7 months between the first and second doses may be as effective against condyloma in girls and women initiating vaccination under 20 years as a three-dose schedule. Results from this nationwide study support immunogenicity data from clinical trials.

Incidence of new-onset autoimmune disease in girls and women with pre-existing autoimmune disease after quadrivalent human papillomavirus vaccination: a cohort study.

OBJECTIVE: To assess whether quadrivalent human papillomavirus (qHPV) vaccination is associated with increased incidence of new-onset autoimmune disease in girls and women with pre-existing autoimmune disease. METHODS: This register-based open cohort study included all girls and women between 10 and 30 years of age in Sweden in 2006-2012 diagnosed with at least one of 49 prespecified autoimmune diseases (n = 70 265). Incidence rate ratios were estimated for new-onset autoimmune disease within 180 days of qHPV vaccination using Poisson regression adjusting for, country of birth, parental country of birth, parental income and parental education. RESULTS: A total of 70 265 girls and women had at least one of the 49 predefined autoimmune diseases; 16% of these individuals received at least one dose of qHPV vaccine. In unvaccinated girls and women, 5428 new-onset autoimmune diseases were observed during 245 807 person-years at a rate of 22.1 (95% CI 21.5-22.7) new events per 1000 person-years. In vaccinated girls and women, there were 124 new events during 7848 person-years at a rate of 15.8 (95% CI 13.2-18.8) per 1000 person-years. There was no increase in the incidence of new-onset autoimmune disease associated with qHPV vaccination during the risk period; on the contrary, we found a slightly reduced risk (incidence rate ratio 0.77, 95% CI 0.65-0.93). CONCLUSION: In this nationwide study, qHPV vaccination was not associated with increased incidence of new-onset autoimmune disease in girls and women with pre-existing autoimmune disease.