Modelling the potential clinical and economic impact of universal immunisation with nirsevimab versus standard of practice for protecting all neonates and infants in their first respiratory syncytial virus season in Spain.

BACKGROUND: Respiratory syncytial virus (RSV) is associated with substantial morbidity among infants. This study modelled the potential public health and economic impact of nirsevimab, a long-acting monoclonal antibody, as an immunoprophylactic strategy for all infants in Spain in their first RSV season. METHODS: A static decision-analytic model of the Spanish birth cohort during its first RSV season was developed to estimate the impact of nirsevimab on RSV-related health events and costs versus the standard of practice (SoP). Spain-specific costs and epidemiological data were used as model inputs. Modelled outcomes included RSV-related outpatient visits, emerging room (ER) visits, hospitalisations - including pediatric intensive care unit (PICU) admission, mechanical ventilation, and inpatient mortality. RESULTS: Under the current SoP, RSV caused 151,741 primary care visits, 38,798 ER visits, 12,889 hospitalisations, 1,412 PICU admissions, and 16 deaths over a single season, representing a cost of €71.8 million from a healthcare payer perspective. Universal immunisation of all infants with nirsevimab was expected to prevent 97,157 primary care visits (64.0% reduction), 24,789 ER visits (63.9%), 8,185 hospitalisations (63.5%), 869 PICU admissions (61.5%), and 9 inpatient deaths (52.6%), saving €47.8 million (62.4%) in healthcare costs. CONCLUSIONS: These results suggest that immunisation with nirsevimab of all infants experiencing their first RSV season in Spain is likely to prevent thousands of RSV-related health events and save considerable costs versus the current SoP.

Safety and tolerability of cell culture-derived and egg-derived trivalent influenza vaccines in 3 to <18-year-old children and adolescents at risk of influenza-related complications.

BACKGROUND: This descriptive, non-comparative, phase III study evaluated the safety and tolerability of cell culture-derived (TIVc) and egg-derived (TIV) seasonal influenza vaccines in children at risk of influenza-related complications. METHODS: Four hundred and thirty subjects were randomized 2:1 to TIVc or TIV. Subjects aged 3 to <9 years received one dose (if previously vaccinated, n=89) or two doses (if not previously vaccinated, n=124) of the study vaccines; the 9 to <18-year-olds (n=213) received one dose. Reactogenicity was assessed for 7 days after vaccination; safety was monitored for 6 months. RESULTS: After any vaccination, the most frequently reported solicited local adverse event (AE) was tenderness/pain (TIVc 44%, 66%, 53% and TIV 56%, 51%, 65% in the age groups 3 to <6 years, 6 to <9 years, and 9 to <18 years, respectively) and the systemic AE was irritability (22% TIVc, 24% TIV) in 3 to <6-year-olds and headache in 6 to <9-year-olds (20% TIVc, 13% TIV) and 9 to <18-year-olds (21% TIVc, 26% TIV). There were no cases of severe fever (≥40°C). No vaccine-related serious AEs were noted. New onset of chronic disease was reported in ≤1% of subjects. CONCLUSION: TIVc and TIV had acceptable tolerability and similar safety profiles in at-risk children (NCT01998477).