Respiratory syncytial virus (RSV) infection is a frequent cause of hospitalisation in the first few months of life; however, this risk rapidly decreases with age. Nirsevimab immunoprophylaxis was approved in the European Union for the prevention of RSV-associated lower respiratory tract disease in infants during their first RSV season. We evaluated the effectiveness of nirsevimab in preventing hospitalisations for confirmed RSV infection and the impact of a strategy of immunisation at birth. A population-based cohort study was performed in Navarre, Spain, where nirsevimab was offered at birth to all children born from October to December 2023. Cox regression was used to estimate the hazard ratio of hospitalisation for PCR-confirmed RSV infection between infants who received and did not receive nirsevimab. Of 1177 infants studied, 1083 (92.0%) received nirsevimab. The risk of hospitalisation for RSV was 8.5% (8/94) among non-immunised infants versus 0.7% (8/1083) in those that were immunised. The estimated effectiveness of nirsevimab was 88.7% (95% confidence interval, 69.6–95.8). Immunisation at birth of infants born between October and December 2023 prevented one hospitalisation for every 15.3 immunised infants. Immunisation of children born from September to January might prevent 77.5% of preventable hospitalisations for RSV in infants born in 2023–2024. These results support the recommendation of nirsevimab immunisation at birth to children born during the RSV epidemic or in the months immediately before to prevent severe RSV infections and alleviate the overload of paediatric hospital resources.

Background: Respiratory syncytial virus (RSV) is a major cause of acute respiratory infection that can lead to complications in risk groups. Aim: We aimed to estimate the incidence of RSV hospitalisation in adults, determine the risk factors and characterise priority groups for prevention. Methods: This population-based cohort study included adults 60 years and older in Navarre, Spain, in seasons 2016/17 to 2019/20. We estimated the rate of RSV hospitalisation confirmed by PCR and evaluated risk factors using Poisson regression. Results: Within 642,622 person-years analysed, we detected 544 RSV hospitalisations (average annual rate: 84.7/100,000). The rate varied among seasons between 59.7 and 95.6 per 100,000. The rate ratio of hospitalisation was higher than 3 from the age of 75 years and around 7 in the 85–94 years age group compared with those aged 60–64 years. Nursing home residence, functional dependence, haematological cancer, chronic obstructive pulmonary disease (COPD), asthma, cardiovascular disease, severe obesity, diabetes and chronic kidney disease were independent risk conditions. Rate of RSV hospitalisation was higher than 300 per 100,000 among people with haematological cancer or nursing home residence, those aged ≥ 75 years with COPD or functional dependence, and those aged ≥ 85 years with asthma or cardiovascular disease. These groups represented 13.2% of all adults aged ≥ 60 years and 50.7% of their RSV hospitalisations. On average, these groups had one RSV hospitalisation per 307 person-years. Conclusion: Advanced age, in addition to nursing home residence, functional dependence and some comorbidities define priority groups for RSV vaccination.

Objective: We aimed to estimate autumn 2023 COVID‐19 vaccine effectiveness (CVE) in preventing hospitalizations due to COVID‐19 until September 2024.Methods: We performed a test‐negative case–control study nested in the cohort of adults aged ≥ 45 years with indication of autumn 2023 COVID‐19 vaccination in Navarre, Spain. The study included patients hospitalized for severe acute respiratory infection (SARI) and tested by polymerase chain reaction between October 2023 and September 2024. The COVID‐19 vaccination statuses in the current and previous seasons were compared between confirmed COVID‐19 cases and test‐negative controls. CVE was estimated as (1 − adjusted odds ratio) × 100.Results: Of 4051 SARI hospitalized patients included in the study, 474 (12%) were confirmed for COVID‐19. CVE to prevent COVID‐19 hospitalizations was 32% (95% confidence interval [CI], 11%–48%) on average for the year and 38% (95% CI, 17%–54%) among people aged ≥ 65 years. However, estimates for current‐season vaccination were 51% (95% CI, 30%–66%), 50% (95% CI, 16%–70%), and 0% (95% CI, −42% to 30%) for 7 to 89, 90 to 179, and ≥ 180 days between vaccination and COVID‐19 diagnosis, respectively. The residual effect of previous‐season vaccination was not statistically significant (14%; 95% CI, −20% to 39%). CVE was moderate in preventing COVID‐19 hospitalizations between October 2023 and March 2024 (50%; 95% CI, 28%–65%), and null between April and September 2024 (6%; 95% CI, −41% to 38%). The vaccine averted 19% of COVID‐19 hospitalizations. On average, 963 doses of vaccine were necessary to prevent one COVID‐19 hospitalization.Conclusions: CVE was moderate in preventing COVID‐19 hospitalizations during the 2023–2024 season, but decreased 6 months after vaccination.

Fundamento. La infección por el virus respiratorio sincitial (VRS) es la principal causa de hospitalización en lactantes. En 2022 se autorizó el nirsevimab en la Unión Europea para prevenir la enfermedad respiratoria grave por VRS durante el primer año de vida. Evaluamos la efectividad de la inmunoprofilaxis con nirsevimab en recién nacidos para prevenir hospitalizaciones por VRS en Navarra durante las dos primeras temporadas de implementación. Métodos. Se ofreció nirsevimab a las cohortes de recién nacidos de octubre a diciembre de 2023 y de septiembre a diciembre de 2024, que se siguieron hasta febrero del año siguiente. Se consideraron casos a las hospitalizaciones por VRS confirmadas por PCR. Mediante regresión de Cox se estimó la razón de riesgos de hospitalización por VRS de inmunizados frente a no inmunizados. Resultados. Se ofreció nirsevimab a 2.699 recién nacidos, y 2.541 lo recibieron (94,1%). Se registraron 17 hospitalizaciones por VRS en la temporada 2023-2024 y 24 en la 2024-2025. El riesgo promedio de hospitalización por VRS fue 7,6% en no inmunizados y 1,1% en inmunizados. La efectividad promedio del nirsevimab para prevenir hospitalizaciones por VRS fue 79,5% (IC95%: 59,2-89,7), 89,9% en la temporada 2023-2024 y 52,8% en la 2024-2025, sin diferencias significativas entre ambas (p=0,055). La inmunoprofilaxis previno en promedio una hospitalización por VRS por cada 22,6 inmunizados. Conclusiones. La inmunoprofilaxis con nirsevimab resultó efectiva para prevenir hospitalizaciones por VRS y alivió la sobrecarga de ingresos pediátricos. Ante la posibilidad de casos en inmunizados, debe complementarse con otras medidas preventivas.

Assessment of the level of knowledge and attitudes regarding COVID-19 and preventive measures in household contacts of COVID-19 cases after the acute phase of the pandemic. Survey among household contacts of COVID-19 cases conducted in healthcare centers in Navarre (1) and Catalonia (8) between May 2022 and July 2023. The frequency of use of preventive measures and the knowledge and attitudes towards COVID-19 were assessed through 12 items. 215 contacts participated who correctly used the preventive measures (>85%), except for facemasks (35.8%) and interpersonal distance (47%); >85% showed adequate knowledge (5/6 items) and >80% had a positive attitude (3/6 items). Moreover, 54.7% considered that COVID-19 negatively affected their life and 54.1% that it is better to develop immunity by getting infected than by vaccination. Household contacts show a correct level of knowledge and positive attitude towards the disease and its preventive measures.

This study aims to describe the long-term changes in the knowledge of, and attitudes towards, COVID-19 and its preventive measures in northern Spain. A telephonic survey was performed among household contacts of COVID-19 cases in Catalonia and Navarre between May 2022 and December 2023. Knowledge and attitudes were assessed through 12 questions using a Likert scale, and responses were grouped as correct or incorrect. The change from baseline to the 6-month follow-up was evaluated with the absolute difference (AD) using the proportion of correct answers. At baseline, 299 subjects were contacted, of whom 63.2% (189) completed the 6-month follow-up. Correct knowledge of transmission (>85%) and the use of preventive measures (>92%) were observed at baseline and maintained over time. The attitudes towards face mask use remained adequate over the course of six months (>79%). However, attitudes regarding the use of face masks indoors (AD = −16.4%; p < 0.001) and those who thought that COVID-19 had a negative impact on their lives (AD = −16.5%; p < 0.001) decreased after 6 months. In the post-acute phase of the pandemic, household contacts maintained the correct level of knowledge towards COVID-19, while some attitudes decreased. These results should serve as a guide for health policy makers in decision-making in case of a new increase in the incidence of SARS-CoV-2.