Flu and RSV 2018–19 season and vaccine effectiveness against the need for hospital flu treatment in Guadalajara province, Spain

Abstract

Introduction

The objective was to estimate the effectiveness of inactivated trivalent vaccine (VE) in preventing hospital flu care (HFC) in Guadalajara, Castile-La Mancha (CLM), Spain, 2018–19 season.

Material and methods

Retrospective cohort study (40/2018 to 13/2019 weeks). Sources: Microbiology programme; electronic medical history; population census (INE, 1/7/2018). Cases: Population requiring HFC (hospital emergencies and/or emergency observation unit and/or hospital admissions), confirmed by antigenic test and/or PCR. Preventive fractions [PFv(vaccinated) and PFp(population)] and necessary number of patients to be vaccinated (NNV) were calculated.

Results

228 HFT occurred [cumulative incidence rate (IR) = 8.9/10⁴; ≥65 years = 65%; vaccination coverage = 13% (≥65 years = 58%; mortality = 9%); maximum incidence in the 6th week (IR = 1.7/10⁴) (in CLM, in 4th)]. Highest peak of RSV occurred in the 3rd (in CLM, in the 52th). PFv (14–65 years) was 96% (PFp = 58%) and in ≥65, 32% (PFp = 21%). NNV = 414. As in Spain, influenza virus A predominated, with A(H3N2) being 13% more prevalent (strain not included in the vaccine).

Conclusions

The season was delayed by sustained VRS circulation. The VE was lower than the national one. It is be essential to promote future campaigns to improve vaccination coverage.

Resumen

Introducción

El objetivo fue estimar la efectividad de la vacuna (EV) trivalente inactivada para prevenir atenciones hospitalarias por gripe (AHG) en Guadalajara, Castilla-La Mancha (CLM), España, temporada 2018-2019.

Material y métodos

Estudio de cohortes retrospectivo; semanas 40/2018 a 13/2019. Fuentes: Programa Microbiología; historia clínica electrónica; censo poblacional (INE, 1/7/2018). Casos: AHG (urgencias y/u observación de urgencias o ingreso), confirmadas mediante prueba antigénica o PCR. Se calcularon: fracciones preventivas ([FPv(vacunados) y FPp(poblacional)]) y número necesario de pacientes a vacunar (NNV).

Resultados

Hubo 228 AHG (tasa incidencia [TI] acumulada = 8,9/10⁴; ≥65 años = 65%; cobertura vacunal = 13% [≥65 años = 58%]; mortalidad = 9%); con máxima incidencia en la semana 6.ª (TI = 1,7/10⁴) (en CLM, en la 4.ª). El mayor pico de VRS ocurrió en la 3.ª semana (en CLM, en la 52). La FPv entre 14-65 años fue del 96% (FPp = 58%) y en ≥65, del 32% (FPp = 21%). NNV = 414. Como en España, predominó el virus A, siendo A(H3N2) un 13% más prevalente (cepa no concordante con la vacunal).

Conclusiones

La temporada se retrasó por una sostenida circulación del VRS. La EV resultó inferior a la nacional. Sería imprescindible impulsar próximas campañas para mejorar la cobertura.