Respiratory Syncytial Virus (RSV) Burden in Infants in the Kingdom of Saudi Arabia and the Impact of All-Infant RSV Protection: A Modeling Study.

INTRODUCTION: Respiratory syncytial virus (RSV) represents a considerable burden on the healthcare system and hospital resources. This study explored the impact of universal immunoprophylaxis with long-acting monoclonal antibody (nirsevimab) during infants' first RSV season on RSV-induced health events and related costs in the Kingdom of Saudi Arabia (KSA). METHODS: The burden of RSV-induced health events and related costs under the current standard of practice (SoP) and the impact of universal immunoprophylaxis with nirsevimab was estimated using a static decision-analytic model in a cohort of infants experiencing their first RSV season in the KSA. The model estimated hospital admissions (including pediatric intensive care unit [PICU] admissions and mechanical ventilation [MV]), emergency room (ER) visits, primary care (PC) visits, long-term sequelae, and RSV mortality. RESULTS: The model estimated that under the current SoP, RSV results in 17,179-19,607 hospitalizations (including 2932-3625 PICU and 172-525 MV admissions), 57,654-191,115 ER visits, 219,053-219,970 PC visits, 14 deaths, 12,884-14,705 cases of recurrent wheezing, and a total cost of SAR 480-619 million. Universal nirsevimab immunoprophylaxis was estimated to avert 58% of hospitalizations (58% PICU admissions, 58% MV episodes), 53% of ER visits, 53% of PC visits, 58% of episodes of recurrent wheezing, 8 deaths, and result in savings of SAR 274-343 million in total healthcare cost. CONCLUSION: Compared with current SoP, an nirsevimab immunoprophylaxis strategy in the KSA for all infants during their first RSV season was estimated to dramatically decrease healthcare resource use, and economic burden associated with RSV.

Expected Impact of Universal Immunization With Nirsevimab Against RSV-Related Outcomes and Costs Among All US Infants in Their First RSV Season: A Static Model.

BACKGROUND: Respiratory syncytial virus (RSV) is associated with substantial morbidity in the United States, especially among infants. Nirsevimab, an investigational long-acting monoclonal antibody, was evaluated as an immunoprophylactic strategy for infants in their first RSV season and for its potential impact on RSV-associated, medically attended lower respiratory tract illness (RSV-MALRTI) and associated costs. METHODS: A static decision-analytic model of the US birth cohort during its first RSV season was developed to estimate nirsevimab's impact on RSV-related health events and costs; model inputs included US-specific costs and epidemiological data. Modelled RSV-related outcomes included primary care and emergency room visits, hospitalizations including intensive care unit admission and mechanical ventilations, and RSV-related mortality. RESULTS: Under current standard of care, RSV caused 529 915 RSV-MALRTIs and 47 281 hospitalizations annually, representing $1.2 billion (2021 US dollars [USD]) in costs. Universal immunization of all infants with nirsevimab is expected to reduce 290 174 RSV-MALRTI, 24 986 hospitalizations, and expenditures of $612 million 2021 USD. CONCLUSIONS: An all-infant immunization strategy with nirsevimab could substantially reduce the health and economic burden for US infants during their first RSV season. While this reduction is driven by term infants, all infants, including palivizumab-eligible and preterm infants, would benefit from this strategy.