Human papillomavirus vaccines effectiveness to prevent genital warts: A population-based study using health system integrated databases, 2009-2017.

OBJECTIVES: To assess the effectiveness of the HPV vaccines in preventing genital warts (GW) in women aged 14-23 years and to estimate the incidence of GW in the whole population aged from 14 to 65. DESIGN: Population-based retrospective cohort study using real-world data from the Valencia health system Integrated Databases (VID). STUDY POPULATION: All subjects aged 14-65 years residing in the Valencia Region during 2009-2017 (n = 4,492,724), including a cohort of 563,240 females aged 14-23 years followed-up for the vaccine effectiveness (VE) estimations. MAIN OUTCOME MEASURES: Incident cases of GW defined as the first activation of GW-related codes (ICD-9-CM 078.11 or ICD-10-CM A63.0) in hospital, primary and specialized care during the study period. Adjusted VE was estimated as (1-Relative Risk (RR)) × 100 by a negative binomial Bayesian model. RESULTS: There were 23,049 cases of GW in the overall population and 2,565 in the females' cohort 14-23 years old. The incidence rate (IR) (in 100,000 persons-year) was 69.1 (95% CI 68.21-69.99) in the population overall, being higher in men (72.73; 95% CI 71.45-74.04). The IR of GW was 104.08 (95% CI 100.79-108.94) in the cohort of young women. The RR of GW increased with age from 14 to 21 years, reaching a plateau from 21 to 23. The VE of a complete schedule was 74% (95% CrI 68-79) for quadrivalent HPV vaccine (HPV4v). No effectiveness was seen with a full vaccination course with the bivalent HPV vaccine (HPV2v) in girls up to 21 years old. GW IR tends to be higher in unvaccinated cohorts covered by HPV4v vaccine than in unvaccinated cohorts not covered by HPV4v vaccine. CONCLUSIONS: A complete HPV4v vaccination schedule was 74% effective in reducing GW in our population. Our results also suggest an indirect protection to unvaccinated and HPV2v vaccinated girls.

Herpes zoster risk and burden of disease in immunocompromised populations: a population-based study using health system integrated databases, 2009-2014.

BACKGROUND: Estimate the incidence of herpes zoster (HZ), its complications and healthcare utilization rates in adults (≥ 18-years-old) with a wide range of immunocompromised (IC) conditions compared to IC-free cohort. METHOD: A population-based retrospective study using the Valencia healthcare Integrated Databases (VID) (2009-2014). HZ and IC were defined using ICD-9 codes in primary care (PC) and hospitalization registers. Incidence rates (IR), risk of HZ, HZ-recurrence, HZ-complications and healthcare utilization rates were estimated in the IC-cohort compared to IC-free. RESULTS: The study population consisted of 4,382,590 subjects, of which 578,873 were IC (13%). IR (in 1000 persons-year) of HZ overall, in IC and in IC-free cohort was 5.02, 9.15 and 4.65, respectively. IR of HZ increased with age in both cohorts and it was higher for all IC conditions studied, reaching up to twelvefold in subjects with stem cell transplantation. IC subjects had 51% higher risk of developing HZ, 25% higher HZ-recurrence and the risk of HZ-complications was 2.37 times higher than in IC-free. HZ-related healthcare utilization was higher in the IC-cohort than in IC-free (number of hospitalizations 2.93 times greater, hospital stays 12% longer, 66% more HZ-specialist visits, 2% more PC visits, sick leaves 18% longer and 20% higher antiviral dispensation). CONCLUSIONS: Patients suffering from all the IC conditions studied are at higher risk of developing HZ, HZ-recurrence and post-herpetic complications, which implies a substantial morbidity and a high consumption of resources. These results should be considered for vaccine policy implementation.