LAUSR

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.