Search

Background: In 2014 the Netherlands switched from 3 to 2 doses for routine vaccination with the prophylactic bivalent human papillomavirus (HPV) vaccine. The current study explored whether antibody responses are noninferior after 2 versus 3 doses in girls.Methods: Girls vaccinated at 12 years of age with 2 (at 0 and 6 months) or 3 doses (at 0, 1, and 6 months) of the bivalent HPV vaccine were identified in the vaccination registration system. Type-specific antibody concentrations and avidity against HPV-16/18/31/33/45/52/58 were assessed. Analyses were stratified for time since the first dose (0-2, 2-3, 3-4, or 4-4½ years). Noninferiority (margin, 0.5) of the 2- versus the 3-dose schedule in girls was examined.Results: Geometric mean concentrations (GMCs) for vaccine types were only noninferior for 2 versus 3 doses for HPV-18 (at 2-3 years after the first dose; GMC ratio, 0.89; 95% confidence interval, .57-1.38) For vaccine types and cross-protective types (HPV-16/18/31/33/45), the avidity index was noninferior for the 2-dose compared with the 3-dose schedule, except for HPV-31 at 4-4½ years after the first dose and HPV-33 at 3-4 and 4-4½ years.Conclusions: GMCs for HPV-16/18 were not noninferior for 2 versus 3 doses, except for HPV-18 (at 2-3 years after first dose). However, antibody avidity for these types showed noninferiority, independent of concentrations. [ABSTRACT FROM AUTHOR]

Background: There is ongoing debate about the possible protective effect of the bivalent human papillomavirus (2vHPV) vaccine, targeting oncogenic types HPV-16/18, against anogenital warts (AGWs), commonly attributed to HPV-6/11. We performed a retrospective registry-based open cohort study to assess the effect of 2vHPV vaccination on AGWs., Methods: We linked general practice (ie, primary care) data from women born between 1993 and 2002, who had been eligible for HPV vaccination in the Netherlands, to the Dutch national immunization registry on an individual level. Women were followed until their first AGW diagnosis or end of follow-up. Adjusted incidence rate ratios (aIRRs) were estimated using Poisson regression with vaccination status as a time-dependent exposure., Results: We linked data of 96 468 women with a total of 328 019 years observation time and 613 AGW diagnoses (incidence: 1.87/1000 person-years). At the end of follow-up, 61% were 2vHPV vaccinated (≥ 1 dose) of whom 91% were fully vaccinated. The AGW incidence was lower among those with ≥ 1 dose vs 0 doses (aIRR, 0.75 [95% confidence interval {CI}, .64-.88]). The effect of vaccination was stronger after full vaccination (aIRR, 0.72 [95% CI, .61-.86]) and for women who were offered vaccination at 12-13 years of age (aIRR, 0.69 [95% CI, .51-.93]) vs those at 13-16 years of age (aIRR, 0.77 [95% CI, .64-.93])., Conclusions: This is the largest population-based study so far to examine the effect of 2vHPV vaccination on AGWs, with reliable individual information on AGW diagnoses and vaccination status. The results indicate that 2vHPV vaccination partially protects against AGWs, especially when administered in early adolescence., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)