Effectiveness of influenza vaccination in preventing confirmed influenza cases and hospitalizations in Northern Spain, 2023/24 season: A population-based test-negative case-control study.

Objective: We estimated the influenza vaccination effectiveness (IVE) in preventing medical consultations and hospitalizations due to influenza during the 2023/24 season.

Methods: Two test-negative case-control studies analyzed patients who consulted primary healthcare or were hospitalized for respiratory symptoms and were tested for influenza by PCR in the 2023/24 season in Navarre, Spain. Influenza vaccination status in the current and previous seasons was compared between confirmed influenza cases and test-negative controls.

COVID-19 Vaccine Effectiveness in Autumn and Winter 2022 to 2023 Among Older Europeans.

Importance: In the context of emerging SARS-CoV-2 variants or lineages and new vaccines, it is key to accurately monitor COVID-19 vaccine effectiveness (CVE) to inform vaccination campaigns.

Objective: To estimate the effectiveness of COVID-19 vaccines administered in autumn and winter 2022 to 2023 against symptomatic SARS-CoV-2 infection (with all circulating viruses and XBB lineage in particular) among people aged 60 years or older in Europe, and to compare different CVE approaches across the exposed and reference groups used.

Design, Setting, And Participants: This case-control study obtained data from VEBIS (Vaccine Effectiveness, Burden and Impact Studies), a multicenter study that collects COVID-19 and influenza data from 11 European sites: Croatia; France; Germany; Hungary; Ireland; Portugal; the Netherlands; Romania; Spain, national; Spain, Navarre region; and Sweden.

Prevalence of Respiratory Viral Infections in Deceased Persons during the COVID-19 Pandemic Season 2021-2022: A Population-Based Observational Study.

Although the omicron variant of SARS-CoV-2 circulated intensely during the 2021-2022 season, many patients with severe acute respiratory disease tested negative for COVID-19. The aim of this study was to assess the presence of different respiratory viruses in deceased persons. The proportion of deceased persons with respiratory viral infections in the 2021-2022 season in Navarre, Spain, was estimated considering all deaths caused by confirmed COVID-19 according to the epidemiological surveillance and the results of multiplex PCR tests for respiratory viruses performed in a sample of deceased persons with a cause of death other than COVID-19.

COVID-19 vaccine effectiveness against symptomatic infection with SARS-CoV-2 BA.1/BA.2 lineages among adults and adolescents in a multicentre primary care study, Europe, December 2021 to June 2022.

BackgroundScarce European data in early 2021 suggested lower vaccine effectiveness (VE) against SARS-CoV-2 Omicron lineages than previous variants.AimWe aimed to estimate primary series (PS) and first booster VE against symptomatic BA.1/BA.