Respiratory Syncytial Virus: A WAidid Consensus Document on New Preventive Options

Abstract

Background/Objectives: Respiratory syncytial virus (RSV) is a leading cause of respiratory infections, particularly affecting young infants, older adults, and individuals with comorbidities. Methods: This document, developed as a consensus by an international group of experts affiliated with the World Association of Infectious Diseases and Immunological Disorders (WAidid), focuses on recent advancements in RSV prevention, highlighting the introduction of monoclonal antibodies (mAbs) and vaccines. Results: Historically, RSV treatment options were limited to supportive care and the monoclonal antibody palivizumab, which required multiple doses. Recent innovations have led to the development of long-acting mAbs, such as nirsevimab, which provide season-long protection with a single dose. Nirsevimab has shown high efficacy in preventing severe RSV-related lower respiratory tract infections (LRTIs) in infants, reducing hospitalizations and ICU admissions. Additionally, new vaccines, such as RSVpreF and RSVpreF3, target older adults and have demonstrated significant efficacy in preventing LRTIs in clinical trials. Maternal vaccination strategies also show promise in providing passive immunity to newborns, protecting them during the most vulnerable early months of life. This document further discusses the global burden of RSV, its economic impact, and the challenges of implementing these preventative strategies in different healthcare settings. Conclusions: The evidence supports the integration of both passive (mAbs) and active (vaccines) immunization approaches as effective tools to mitigate the public health impact of RSV. The combined use of these interventions could substantially reduce RSV-related morbidity and mortality across various age groups and populations, emphasizing the importance of widespread immunization efforts.

Keywords: RSV; RSV vaccine; lower respiratory tract infections; maternal immunization; monoclonal antibodies; nirsevimab.

Figure A1

Schematic comparison of the seasonal immunization granted by nirsevimab (5 months after the delivery, subfigure (a)) and by the maternal vaccination strategy (6 months after the birth, subfigure (b)).

Figure 1

Time trend of respiratory specimens collected since 2016 in EU countries and the corresponding prevalence rate of positive specimens. Original elaboration from data reported by the ECDC Atlas of Infectious Diseases (https://atlas.ecdc.europa.eu/public/index.aspx), accessed on 6 November 2024 [141].

Figure 2

Strategy for the delivery of nirsevimab as recommended by the German Standing Committee on Vaccinations (STIKO) [203].

Figure 3

Summary of Vaccine Efficacy with corresponding 95% Confidence Intervals (95%CI) in the prevention of lower respiratory tract illnesses (LRTI) with three or more findings (a) and with two clinical findings (b) during the first and second respiratory syncytial virus (RSV) season in adults ≥ 60 years [28,87,210,213,221,241,242,243].

Figure 4

Summary of the decline of Vaccine Efficacy (reported with their corresponding 95% Confidence Intervals [95%CI]) in the prevention of lower respiratory tract illnesses (LRTI) three or more findings during the first and second respiratory syncytial virus (RSV) season [28,87,210,213,221,241,242,243,257]. Preliminary data on season 3 of RSVpreF3 was retrieved from the ACIP Meeting of 24 October 2024 [258].

Figure 5

Summary of current recommendations for the delivery of RSV preventive measures in adults and children, as provided by the United States CDC and ACIP [237,304,305,306].