Influenza and Other Respiratory Viruses最新文献

Controlled human infection models (CHIMs) are a critical tool for the understanding of infectious disease progression, characterising immune responses to infection and rapid assessment of vaccines or drug treatments. There is increasing interest in using CHIMs for vaccine development and an obvious need for widely available and fit-for-purpose challenge agents. Inno4Vac is a large European consortium working towards accelerating and de-risking the development of new vaccines, including the development of CHIMs for influenza, respiratory syncytial virus and Clostridioides difficile. This report (in two parts) summarises a workshop held at the MHRA in 2021, focused on how to select CHIM candidate strains of influenza and respiratory syncytial virus (RSV) based on desirable virus characteristics and which immune assays would provide relevant information for assessing pre-existing and post-infection immune responses and defining correlates of protection. This manuscript (Part 1) summarises presentations and discussions centred around influenza CHIMs and immune assays (a second manuscript summarises RSV CHIM and immune assays: Inno4Vac workshop report Part 2: RSV CHIM strain selection and immune assays for RSV CHIM studies, November 2021, MHRA, UK).

Background: Clinical data on patients infected with influenza B Victoria (BV) after the approval of baloxavir is lacking.

Methods: This observational study of the Japanese 2023-2024 influenza season analyzed data from 25 outpatients with A(H1N1)pdm09, 36 with A(H3N2), and 65 with BV. Viral samples were collected before and after administering an antiviral (70 patients received baloxavir and 56 received a neuraminidase inhibitor), on days 1, 5, and 10. Isolated viruses after culturing were amplified using RT-PCR and sequenced to detect mutations of concern, including acidic protein (PA)-amino acid (AA) E23X/I38X for influenza A and M34X/I38X for BV. Fever and symptoms were tracked via self-reporting diaries.

Results: No PA-AA-substituted virus was detected from 126 pre-treatment samples. In the baloxavir cohort, one (7.1%, 1/14) PA I38F-substituted A(H1N1)pdm09 and two (11.1%, 2/18) PA I38T-substituted A(H3N2) viruses were isolated on day 5 but not on day 10. No (0%, 0/37) PA-AA-substituted BV was detected on day 5 or after. The virus isolation rate on day 5 was higher among patients with BV than with influenza A in both baloxavir (35.1% vs. 14.3% for A(H1N1)pdm09 and 16.7% for A(H3N2)) and oseltamivir-treated patients (44.4% vs. 0% for A(H1N1)pdm09 and 33.3% for A(H3N2)). Patients with PA-AA-substituted influenza A after baloxavir administration did not have longer fever duration than those without virus isolation or with wild-type virus on day 5, for both A(H1N1)pdm09 and A(H3N2).

Conclusions: Baloxavir-resistant variants were not detected in influenza BV before treatment, as with A. The emergence of PA-AA-substituted influenza A after baloxavir administration was temporal and did not cause prolonged symptoms. No baloxavir-resistant BV variants were observed after baloxavir administration.

Background: Respiratory syncytial virus (RSV) and influenza virus are major viral etiologies of pediatric lower respiratory tract infection, but comparative data on inpatient burden are lacking.

Methods: Using a large-scale health claims database in Japan, we identified patients under 5 years of age with a confirmed RSV or influenza diagnosis as an outpatient or inpatient between 2011 and 2022. Hospitalization rate, inpatient characteristics, various in-hospital outcomes/complications, and healthcare resource utilization were described.

Results: A total of 176,911 RSV-confirmed outpatients, 153,383 influenza-confirmed outpatients, 90,413 RSV-confirmed hospitalizations, and 11,186 influenza-confirmed hospitalizations were identified. Among outpatients, 24.7% of RSV infection and 2.8% of influenza cases required hospitalization within 1 week. There was no co-morbidities/prematurity for 95.0% of RSV hospitalizations and 96.5% of influenza hospitalizations. Proportions of in-hospital outcomes/complications were (RSV infection vs. influenza): oxygen use 47.6% vs. 14.8%, mechanical ventilation 2.1% vs. 0.7%, pneumonia 33.6% vs. 12.8%, otitis media 7.7% vs. 2.3%, febrile seizure 1.5% vs. 34.4%, encephalitis/encephalopathy 0.1% vs. 0.5%, myocarditis < 0.1% vs. 0.6%, antibiotics prescription 48.0% vs. 24.4%. The mean inpatient stay was 6.1 vs. 4.3 days at direct medical costs of 435,744 vs. 315,809 JPY/patient. These trends held true in age-stratified data. In-hospital death occurred in 31 RSV infection and 6 influenza cases.

Conclusions: Although both infections resulted in substantial burden, RSV infection led to more frequent hospitalizations, worse in-hospital outcomes, longer inpatient stays, higher medical costs, and more frequent antibiotics prescription compared to influenza. Most RSV hospitalizations occurred among healthy term children, emphasizing the need for prevention measures in all children.

The Global Initiative on Sharing All Influenza Data, a public-access database for sharing severe acute respiratory syndrome coronavirus 2 genomic sequencing data, has received significantly less data from African countries compared to the global total. Furthermore, the contribution of these data was infrequent and, for some countries, non-existent. The primary aim of this review is to identify the technological barriers to routine genomic surveillance in Africa. PubMed and Google Scholar were searched for the relevant articles, and other eligible articles were identified from the reference list examination according to the PRISMA checklist. Eighty-four full-text articles were analysed for eligibility, and 49 published full-texted articles were included in the final qualitative analysis. The main technological barriers identified were limited genomic surveillance capacity, limited genomic sequencing infrastructure, lack of resources and skilled or trained scientists, and the high cost of importing, establishing, and maintaining a genomic sequencing facility. The Africa Pathogen Genomics Initiative aims to improve genomic surveillance capacity across Africa, through resources, training, education, infrastructure, and regional sequencing centres. Furthermore, collaborations between African governments and international partners or national, private, and academic institutions are imperative to sustain genomic surveillance in Africa, and investment in genomic sequencing and research and development is paramount. Longer turnaround times interfere with global viral evolution monitoring and national implementation of effective policies to reduce the burden and disease. Establishing effective genomic surveillance systems guides public health responses and vaccine development for diseases endemic in Africa.