Respiratory Syncytial Virus Infection in Older Adults: An Update

Abstract

Respiratory syncytial virus (RSV) infection represents one of the most common infections during childhood, with significant morbidity and mortality in newborns and in the early years of life. RSV is a common infection throughout all age groups, largely undetected and underestimated in adults, with a disproportionately high impact in older individuals. RSV infection has a wide range of clinical presentations, from asymptomatic conditions to acute pneumonia and severe life-threatening respiratory distress, including exacerbations of underlying chronic conditions. Overall, the incidence of RSV infections requiring medical attention increases with age, and it is highest among persons ≥ 70 years of age. As a consequence of a combination of an aging population, immunosenescence, and the related increased burden of comorbidities, high-income countries are at risk of developing RSV epidemics. The standard of care for RSV-infected patients remains supportive, including fluids, antipyretics, and oxygen support when needed. There is an urgent need for antivirals and preventive strategies in this population, particularly in individuals at higher risk of severe outcomes following RSV infection. In this review, we describe prevention and treatment strategies for RSV illnesses, with a deep focus on the novel data on vaccination that has become available (Arexvy, GSK, and Abrysvo, Pfizer) for older adults.

Fig. 1

Geographical distribution of the estimated annual respiratory syncytial virus-associated hospitalizations in European Union countries (including the United Kingdom) and Norway in patients aged > 65 years old (data from [17]).

Fig. 2

Structure and genomic RNA of respiratory syncytial virus (Reproduced with permission from [3]). ssRNA single-stranded ribonucleic acid

Fig. 3

Pathogenesis of RSV infections, involving the innate and adaptive immune response. AMs alveolar macrophages, DCs dendritic cells, hAECs human airway epithelial cells, NKs natural killers, PMNs polymorphonuclear cells, RSV respiratory syncytial virus

Fig. 4

Evolution of RSV epidemiology during the COVID-19 pandemic. Reproduced from Ref. [69] (Content source: Centers for Disease Control and Prevention). COVID-19 coronavirus disease 2019, RSV respiratory syncytial virus

Fig. 5

Picture of the effort to track the development of RSV vaccine and mAb candidates worldwide. (Reproduced from the PATH website at www.path.org, April 2024). mAb monoclonal antibody, RSV respiratory syncytial virus, BCG Bacillus Calmette-Guérin, hMPV human metapneumovirus, NIAID National Institute of Allergy and Infectious Diseases, NIH National Institutes of Health, PIV5 Parainfluenza virus 5, SeV Sendai virus, VLP virus-like particle, VRC Vaccine Research Center

Fig. 6

RSVPreF3 OA vaccine efficacy in reducing incidence of RSV-LRTD and acute respiratory infections. (Reproduced with permission from [87]). LRTD lower respiratory tract disease, RSV respiratory syncytial virus