Exploring the antigenic relatedness of influenza virus haemagglutinins with strain-specific polyclonal antibodies

Alternative methods to the standard haemagglutination inhibition (HI) and neutralization tests to probe the antigenic properties of the influenza virus haemagglutinin (HA) were developed in this study. Vaccinia virus recombinants expressing reference HAs were used to immunize rabbits from which polyclonal antibodies were obtained. These antibodies were subtype specific but showed limited intra-subtype strain specificity in ELISA. The discriminatory capacity of these antibodies was, however, markedly increased after adsorption to cells infected with heterologous influenza viruses, revealing antigenic differences that were otherwise undistinguishable by standard HI and neutralization tests. Furthermore, the unadsorbed antibodies could be used to select escape mutants of the reference strain, which after sequencing unveiled amino acid changes responsible of the noted antigenic differences. These procedures therefore provide alternative methods for the antigenic characterization of influenza HA and might be useful in studies of HA antigenic evolution.This work was supported by grants (JAM) GR09/0039, (IC) GR09/0040 and (JAM) SAF2012-31217.S

Laboratory capability and surveillance testing for Middle East respiratory syndrome coronavirus infection in the WHO European Region, June 2013

Since September 2012, over 90 cases of respiratory disease caused by a novel coronavirus, now named Middle East respiratory syndrome coronavirus (MERSCoV), have been reported in the Middle East and Europe. To ascertain the capabilities and testing experience of national reference laboratories across the World Health Organization (WHO) European Region to detect this virus, the European Centre for Disease Prevention and Control (ECDC) and the WHO Regional Office for Europe conducted a joint survey in November 2012 and a follow-up survey in June 2013. In 2013, 29 of 52 responding WHO European Region countries and 24 of 31 countries of the European Union/European Economic Area (EU/EEA) had laboratory capabilities to detect and confirm MERS-CoV cases, compared with 22 of 46 and 18 of 30 countries, respectively, in 2012. By June 2013, more than 2,300 patients had been tested in 23 countries in the WHO European Region with nine laboratory-confirmed MERS-CoV cases. These data indicate that the Region has developed significant capability to detect this emerging virus in accordance with WHO and ECDC guidance. However, not all countries had developed capabilities, and the needs to do so should be addressed. This includes enhancing collaborations between countries to ensure diagnostic capabilities for surveillance of MERS-CoV infections across the European Region.S

Human Metapneumovirus Infections during COVID-19 Pandemic, Spain

We describe an unusual outbreak of respiratory infections caused by human metapneumovirus in children during the sixth wave of COVID-19 in Spain, associated with the Omicron variant. Patients in this outbreak were older than usual and showed more hypoxia and pneumonia, longer length of stay, and greater need for intensive care.This study was partially funded by FIS (Fondo de Investigaciones Sanitarias-Spanish Health Research Fund), grant nos. PI06/0532, PI09/0246, PI12/0129, PI18CIII/00009, PI21CIII/00019, and PI21/00377.S

Predominance of influenza A(H3N2) virus genetic subclade 3C.2a1 during an early 2016/17 influenza season in Europe - Contribution of surveillance data from World Health Organization (WHO) European Region to the WHO vaccine composition consultation for northern hemisphere 2017/18

Erratum to "Predominance of influenza A(H3N2) virus genetic subclade 3C.2a1 during an early 2016/17 influenza season in Europe - Contribution of surveillance data from World Health Organization (WHO) European region to the WHO vaccine composition consultation for northern hemisphere 2017/18". Vaccine. 2018 May 3;36(19):2740-2741. doi: 10.1016/j.vaccine.2017.12.039. PMID: 29274700.During the European 2016/17 influenza season, A(H3N2) viruses have predominated and the majority clustered in genetic subclade 3C.2a1. Genetic analyses showed that circulating viruses have undergone considerable genetic diversification of the haemagglutinin gene from the current vaccine virus A/Hong Kong/4801/2014 (clade 3C.2a), but the antigenic data that is limited by the challenges with the antigenic characterisation of currently circulating A(H3N2) viruses, showed no clear evidence of antigenic change. The recommended A(H3N2) vaccine component for the northern hemisphere 2017/18 influenza season remained unchanged. However, early and mid-season vaccine effectiveness (VE) estimates were suggestive of reduced VE against A(H3N2) viruses.S

Human case of swine influenza A (H1N1), Aragon, Spain, November 2008

A human case of swine influenza A (H1N1) in a 50-year-old woman from a village near Teruel (Aragon, in the north-east of Spain), with a population of about 200 inhabitants, has been reported in November 2008.S

Early estimates of seasonal influenza vaccine effectiveness in Europe among target groups for vaccination: results from the I-MOVE multicentre case-control study, 2011/12

To provide an early estimate of 2011/12 influenza vaccine effectiveness (VE), we conducted a multicentre case-control study based on seven sentinel surveillance networks. We included influenza-like illness cases up to week 7/2012 from the vaccination target groups, swabbed less than eight days after symptom onset. Laboratory-confirmed influenza A(H3) cases were compared to negative controls. Adjusted VE was 43% (95% confidence interval: -0.4 to 67.7), suggesting low to moderate VE against influenza A(H3) in the early 2011/12 season.The I-MOVE network has been funded by the European Centre for Disease Prevention and Control (ECDC) since 2007.S

CCR5 deficiency predisposes to fatal outcome in influenza virus infection

Influenza epidemics affect all age groups, although children, the elderly and those with underlying medical conditions are the most severely affected. Whereas co-morbidities are present in 50% of fatal cases, 25-50% of deaths are in apparently healthy individuals. This suggests underlying genetic determinants that govern infection severity. Although some viral factors that contribute to influenza disease are known, the role of host genetic factors remains undetermined. Data for small cohorts of influenza-infected patients are contradictory regarding the potential role of chemokine receptor 5 deficiency (CCR5-Δ32 mutation, a 32 bp deletion in the CCR5 gene) in the outcome of influenza virus infection. We tested 171 respiratory samples from influenza patients (2009 pandemic) for CCR5-Δ32 and evaluated its correlation with patient mortality. CCR5-Δ32 patients (17.4%) showed a higher mortality rate than WT individuals (4.7%; P = 0.021), which indicates that CCR5-Δ32 patients are at higher risk than the normal population of a fatal outcome in influenza infection.This work was supported by the Instituto de Salud Carlos III (Programa especial de investigación sobre la gripe pandémica GR09/0040 and GR09/0023), Centro de Investigación Biomédica en Red en Enfermedades Respiratorias (CIBERES) and the Spanish Ministry of Science and Innovation (BFU 2011-26175)S

Early estimates of seasonal influenza vaccine effectiveness in Europe, 2010/11: I-MOVE, a multicentre case-control study

We present early estimates (up to week 4 of 2011) of the 2010/11 seasonal influenza vaccine effectiveness in preventing medically attended influenza-like illness(ILI) laboratory confirmed as influenza. Practitioners from seven European sentinel networks systematically swabbed ILI patients. We included patients meeting the European Union ILI case definition and swabbed less than eight days after symptom onset. Laboratory-confirmed influenza cases were compared with negative controls. The adjusted vaccine effectiveness was 42.3% (95% CI: -7.3 to 69.0%), suggesting moderate protection of the seasonal vaccine.The I-MOVE network has been funded by the European Centre for Disease Prevention and Control (ECDC) since 2007.S

Surveillance of Viral Respiratory Infections in the Neonatal Intensive Care Unit-Evolution in the Last 5 Years

Viral respiratory infections (VRIs) in very low birthweight infants can be associated with high rates of morbidity. The COVID-19 pandemic has exerted a strong impact on viral circulation. The purpose of this study is to report on VRIs during NICU admission in infants below 32 weeks' gestation and compare data collected between the pre-and post-COVID-19 pandemic periods. A prospective surveillance study was conducted at a tertiary NICU between April 2016 and June 2022. The COVID-19 post-pandemic period was established as being from March 2020 onwards. Respiratory virus detection was performed by real-time multiplex PCR assays in nasopharyngeal aspirates (NPAs). A total of 366 infants were enrolled. There were no statistical differences between periods regarding infants' birth weight, gestational age, gender distribution, or rates of bronchopulmonary dysplasia. Among the 1589 NPA collected during the pre-COVID-19 period, 8.9% were positive, and among the 1147 NPA collected during the post-pandemic period, only 3% were positive (p < 0.005). The type of viruses detected did not differ according to the study period (pre-COVID19 vs. post-COVID-19): rhinovirus (49.5% vs. 37.5%), adenovirus (22.6% vs. 25%), and human coronavirus (12.9% vs. 16.7%). SARS-CoV-2 was only detected in one patient. In conclusion, the viral profile causing VRI during the pre-COVID-19 and post-COVID-19 era was similar. However, the total number of VRI dropped significantly, most probably due to the global increase in infection prevention measures.This study has been partially supported by ISCIII-Instituto de Salud Carlos III, FIS (Fondo de Investigación Sanitaria-Spanish Health Research Fund) grants PI21CIII/00019, PI18CIII/00009, FI19/00067, PI18/00167, PI21/00896 and PI21/00377.S

Influenza virus infections in infants aged less than two years old

[ES] Introducción: Las infecciones por virus influenza son una importante causa de morbilidad en lactantes. El cuadro clínico es inespecífico y a menudo se infraestima la importancia de lagripe en los menores de 2 años. El objetivo del estudio fue describir las infecciones con firmadas por virus influenza en niños menores de 2 años atendidos en un hospital de segundo nivel. Como objetivo secundario, se pretende comparar las infecciones por gripe en lactantes hospitalizados con las infecciones por virus respiratorio sincitial (VRS) en la misma población. Pacientes y métodos: Estudio descriptivo prospectivo de las infecciones con firmadas por virus influenza en los niños menores de 2 años hospitalizados por fiebre o infección respiratoria entre 1991 y 2003. Para el diagnóstico virológico se realizó inmunofluorescencia y reacción en cadena de la poli merasa en el aspirado nasofaríngeo. Se describen las características clínicas de los pacientes. Se realiza una comparación con un grupo de lactantes de similares características ingresados por infección por VRS. Resultados: Se describen 100 lactantes hospitalizados con infección por virus influenza. Las infecciones gripales supusieron el 4,1 % de los pacientes hospitalizados por procesos respiratorios o fiebre. Se aisló virus influenza tipo A en el 83 % de los casos, tipo B en el 12 % y tipo C en el 5 %. La edad media fue 8,3 +/- 5,9 meses, y los diagnósticos más fre cuentes fueron bronquiolitis en el 38 %, sibilancias recurrentes en el 25%, infección respiratoria de vías altas en el 19% y neumonía en el 9%. Presentaron fiebre superior a 38 °C el 83% de los niños e infiltrado radiológico el 65%. Presentaron hipoxia el 44 % de los niños. En los niños menores de 6 meses la fiebre fue menos frecuente (p = 0,049), y en los diagnósticos predominaron las infecciones respiratorias de vías altas (p = 0,01). Los niños afectados de infección por virus influenza tu vieron mayor edad (p = 0,002), presentaron con mayor frecuencia fiebre (p 38 degrees C was present in 83% of the patients. Radiologic infiltrate was found in 65% of the children. Oxygen saturation less then 95% was present in 44%. In children under 6 months of age fever was less frequent (p = 0.049) and upper respiratory tract infection was more frequent (p = 0.01). Patients with influenza virus infection were older (p = 0.002), more frequently presented fever (p < 0.0001) and radiologic infiltrate (p < 0.001) than infants with RSV infection. Bronchiolitis was more frequent in the RSV group (p = 0.006). Conclusions: Influenza infection is a major cause of respiratory tract disease in hospitalized infants. It is an etiologic cause of bronchiolitis, recurrent wheezing, and fever and radiologic consolidations are frequent. Clinical presentation is milder in children under 6 month of age. The characteristics of influenza infection differ substantially from those of RSV infection.S