Beyfortus (nirsevimab) / AstraZeneca, Sanofi, SOBI - LARVOL DELTA

Real-World Effectiveness of Maternal RSVpreF Vaccination and Durability of Infant Protection. (PubMed, medRxiv) - "In this test-negative study, the effectiveness of the maternal RSVpreF vaccine among infants <6 months was 73.9% against medically attended respiratory syncytial virus (RSV) infection and 86.3% against RSV-associated hospitalization. Maternal RSVpreF and nirsevimab had comparable initial effectiveness, but effectiveness of RSVpreF waned approximately 1.7 times more rapidly."

Journal • Real-world evidence • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Effectiveness of nirsevimab reimmunization against RSV hospitalization during the second season in high-risk children. (PubMed, J Pediatric Infect Dis Soc) - "Results suggest a moderate effectiveness of reimmunization with a second nirsevimab dose against hospitalization for respiratory syncytial virus infection during the second season in high-risk children, although the estimated effectiveness was highly uncertain (42%; 95% confidence interval: -25% to 73%)."

Journal • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Reduced Antibiotic Exposure Is Not Equivalent to Reduced Antibiotic Overuse After Nirsevimab. (PubMed, Clin Infect Dis) - No abstract available

Journal

Late Breaking Abstract - Nirsevimab and Risk of Hospitalization for Wheezing in Early Childhood: A Nationwide French Health Claims–Based Cohort Study (ERS 2026) - "In this large nationwide study, nirsevimab was not associated with a reduced risk of wheezing-related hospitalization during the second year of life.Further studies in other settings and subsequent seasons are needed."

Clinical • HEOR • Late-breaking abstract • Asthma • Immunology • Respiratory Diseases • Respiratory Syncytial Virus Infections

Trends in Bronchiolitis-Related Hospitalizations Across Six Winter Seasons in Nine Italian Hospitals: Impact of Nirsevimab Introduction (ERS 2026) - "Nirsevimab introduction aligned with a large reduction in bronchiolitis hospitalizations and a measurable reshaping of bronchiolitis virology in Italy. Interpreting null within-hospital severity differences requires accounting for residualization and evolving care pathways; early, high-coverage implementation is likely to maximize population benefit."

Clinical • Pulmonary Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Impact of Nationwide Nirsevimab Prophylaxis on Acute Viral Bronchiolitis in Italy (ERS 2026) - "RSV prevention strategies were associated with a marked reduction in bronchiolitis-related healthcare utilization and changes in viral epidemiology. Comorbidities remained a major risk factor for severe disease despite prophylaxis."

Infectious Disease • Pulmonary Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Beyond acute RSV bronchiolitis: age-dependent effects of nirsevimab on readmission and recurrent wheezing (ERS 2026) - "Nirsevimab was associated with reduced RW and fewer readmissions in infants aged 1–6 months, but not in neonates and infants >6 months. Age at admission is relevant for post-bronchiolitis risk stratification. Larger multicentre studies are needed to confirm these results."

Pulmonary Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Changes in the clinical profile of RSV admissions after universal nirsevimab immunization (ERS 2026) - "RSV-positive hospitalizations increased and shifted towards children aged 12–24 months, with higher respiratory severity. Continued surveillance and adequately powered studies are needed to inform preventive strategies beyond the first year of life."

Clinical • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Mutational constraints on RSV F and its neutralization by antibodies. (PubMed, Nature) - "We then perform pseudovirus deep mutational scanning to safely measure how nearly all mutations to F affect its cell entry function and neutralization by IgG and Fab forms of nirsevimab, clesrovimab and several other key antibodies. We use these measurements to enable real-time surveillance of RSV sequences for antibody resistance, and show that resistant strains have arisen sporadically but are at present rare. Overall, our work shows how Fab potency and epitope specificity combine to determine how viral mutations affect antibody neutralization, enables monitoring for natural RSV strains resistant to antibodies of public-health importance, and can help guide development of future antibodies with resilience to viral escape."

Journal • Respiratory Diseases • Respiratory Syncytial Virus Infections

A real-world study evaluating the effectiveness of Nirsevimab, a novel antibody drug, for preventing RSV and other respiratory infections in infants in southern China (ChiCTR) - P4 | N=2150 | Not yet recruiting | Sponsor: Guangzhou Women and Children's Medical Center,Guangzhou Medical University; Guangzhou Women and Children's Medical Center,Guangzhou Medical University

New P4 trial • Real-world evidence • Infectious Disease • Pneumonia • Pulmonary Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

EFFICACY OF SINGLE-DOSE NIRSEVIMAB AGAINST RESPIRATORY SYNCYTIAL VIRUS IN INFANTS: A META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS (CHEST 2026) - No abstract available

Retrospective data • Respiratory Diseases

EFFICACY AND SAFETY OF NIRSEVIMAB FOR PREVENTION OF RESPIRATORY SYNCYTIAL VIRUS-ASSOCIATED LOWER RESPIRATORY TRACT INFECTION IN INFANTS: A SYSTEMATIC REVIEW AND META-ANALYSIS (CHEST 2026) - No abstract available

Retrospective data • Review • Infectious Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Nirsevimab resistance in respiratory syncytial virus-B: virological signal without meaningful clinical impact. (PubMed, Lancet Microbe) - No abstract available

Journal • Respiratory Diseases

Impact of the first nirsevimab immunization campaign on infant RSV-related emergency department visits and hospitalizations in Québec, Canada. (PubMed, Epidemiology) - "The 2024-2025 nirsevimab campaign was associated with a two-thirds reduction in RSV-related hospitalizations and RSV-associated ED visits in Québec among 0-5-month-old infants. ED visits for acute bronchiolitis were also reduced by a third."

Journal • Pulmonary Disease • Respiratory Diseases • Respiratory Syncytial Virus Infections

Nirsevimab effectiveness against RSV-associated hospitalization among young children at increased risk of severe RSV disease during their second RSV season — United States, 22 states, November 2024 – March 2026 (IDWeek 2026) - No abstract available

Clinical • Infectious Disease • Respiratory Syncytial Virus Infections

Evaluation of maternal RSV vaccination and Nirsevimab uptake among children born at University of Washington Medical Center, October 2023—April 2025 (IDWeek 2026) - No abstract available

Clinical • Infectious Disease • Respiratory Syncytial Virus Infections

Implementation and Evaluation of Inpatient Nirsevimab Administration on Respiratory Syncytial Virus Admission Rates and Outcomes (IDWeek 2026) - No abstract available

Clinical • Infectious Disease

Two-season nirsevimab effectiveness against respiratory syncytial virus (RSV) lower respiratory tract disease (LRTD) in healthy term infants immunized during their first season (IDWeek 2026) - No abstract available

Clinical • Infectious Disease • Respiratory Syncytial Virus Infections

Timing and Uptake of Nirsevimab (Beyfortus) Among Infants Born During and Outside of the RSV Season in a Large US Pediatric Primary Care Cohort: Recommendation Adherence, Demographic Trends, and Targeted Catch-Up Opportunities (IDWeek 2026) - No abstract available

Adherence • Clinical • Infectious Disease

Optimization of Nirsevimab Uptake in Stony Brook Children's Ambulatory Setting (IDWeek 2026) - No abstract available

Clinical • Infectious Disease

First Real-World Evidence for the Impact of Nirsevimab National Immunization Plan (NIRS-NIP) on Hospitalizations of infants <1y of Age for Radiographically Confirmed Community-Acquired Alveolar Pneumonia (CAAP): A Population-Based Prospective Study (IDWeek 2026) - No abstract available

Clinical • HEOR • Real-world • Real-world evidence • Infectious Disease

Comparative effectiveness of maternal RSVpreF vaccination and infant nirsevimab against RSV among infants in northern California, 2023-2025 (IDWeek 2026) - No abstract available

HEOR • Infectious Disease • Respiratory Syncytial Virus Infections

Pediatric Immunizations (IDWeek 2026) - "Learning Objectives: At the conclusion of this session, participants will be able to:Describe the current state of RSV vaccine uptake and RSV monoclonal Ab utilizationArticulate influenza vaccine efficacy during the previous influenza seasonDescribe the effectiveness of nirsevimab in preventing hospitalization for RSV"

Clinical • Infectious Disease • Influenza • Respiratory Syncytial Virus Infections

Detection of a Nirsevimab-Resistant RSV-B Variant (F:K68Q) in an Adult with Severe Infection. (PubMed, Infect Dis Ther) - P | "The persistence of a resistant RSV variant in a patient who was immunocompromised without prior exposure to nirsevimab suggests that such variants may circulate and be transmitted. In this context, RSV vaccination of patients who are immunocompromised may not only provide individual protection but also help limit the dissemination of resistant strains."

Journal • Critical care • Hematological Malignancies • Infectious Disease • Lymphoma • Mantle Cell Lymphoma • Oncology • Respiratory Diseases • Respiratory Syncytial Virus Infections • Septic Shock

Respiratory Syncytial Virus-Related Hospitalizations Among Infants Receiving Nirsevimab. (PubMed, JAMA Netw Open) - "This test-negative case-control study found that administration of nirsevimab to infants had high estimated effectiveness in preventing RSV disease severity that requires hospital-based care. The results suggest that nirsevimab has the potential to reduce the burden of RSV."

Journal • Critical care • Infectious Disease • Pediatrics • Respiratory Diseases • Respiratory Syncytial Virus Infections