Respiratory syncytial virus infection in the modern era

Abstract

Purpose of reviewRespiratory syncytial virus (RSV) continues to be a major cause of severe lower respiratory tract infection in infants, young children, and older adults. In this review, changes in the epidemiology of RSV during the coronavirus disease 2019 (COVID-19) pandemic are highlighted together with the role which increased molecular surveillance efforts will have in future in assessing the efficacy of vaccines and therapeutics.Recent findingsThe introduction of nonpharmaceutical intervention (NPIs) strategies during the COVID-19 pandemic between 2020 and 2022 resulted in worldwide disruption to the epidemiology of RSV infections, especially with respect to the timing and peak case rate of annual epidemics. Increased use of whole genome sequencing along with efforts to better standardize the nomenclature of RSV strains and discrimination of RSV genotypes will support increased monitoring of relevant antigenic sites in the viral glycoproteins. Several RSV vaccine candidates based on subunit, viral vectors, nucleic acid, or live attenuated virus strategies have shown efficacy in Phase 2 or 3 clinical trials with vaccines using RSVpreF protein currently the closest to approval and use in high-risk populations. Finally, the recent approval and future use of the extended half-life human monoclonal antibody Nirsevimab will also help to alleviate the morbidity and mortality burden caused by annual epidemics of RSV infections.SummaryThe ongoing expansion and wider coordination of RSV molecular surveillance efforts via whole genome sequencing will be crucial for future monitoring of the efficacy of a new generation of vaccines and therapeutics.

Epidemiology of Respiratory Infections during the COVID-19 Pandemic

“…The COVID-19 pandemic has been accompanied by significant variations in the global incidence of diseases due to the most common non-SARS-CoV-2 respiratory viruses [ 25 , 26 ] and some bacteria [ 27 , 28 ]. The incidence of respiratory infections was initially reduced, although with differences between infecting agents.…”

“…A rapid return to traditional levels was evidenced in some cases. In other cases, low circulation persisted for several months and a return to pre-pandemic levels was reached only after three pandemic years [ 25 , 26 , 27 , 28 ]. Several factors could explain these findings, including the implementation of the various NPIs and the duration of their use.…”

From Forgotten Pathogen to Target for New Vaccines: What Clinicians Need to Know about Respiratory Syncytial Virus Infection in Older Adults

“…Both the G and F proteins are important antigenic targets for immune neutralization. Variability in the F protein correlates with disease severity and effectiveness of monoclonal drug and vaccine development [ 46 ]. There are two subtypes of RSV described, A and B, with significant genomic variation between the two that are simultaneously present in most outbreaks, A subtypes typically causing the more severe disease.…”

Human Milk Oligosaccharides and Respiratory Syncytial Virus Infection in Infants

“…The F protein also promotes the aggregation of cells through the fusion of their plasma membranes, producing the cognate multinucleated syncytia and allowing the transmission of virus from cell to cell. RSV has 2 major antigenic strains, RSV-A and RSV-B, which have distinct epitopes in the F and G proteins in addition to several subtypes [ 3 , 4 ]. RSV-A and RSV-B can cocirculate with alternating dominance annually.…”

“…Sialylated or nonsialylated glycans can serve as binding sites for human rotavirus in a strain-dependent manner [ 62 , 63 ]. Although 2’-FL is more efficient in reducing rotavirus G1P[ 8 ] strain infectivity, 3’-sialyl-lactose (3’-SL) and 6’-sialyl-lactose (6’-SL) are more effective against rotavirus strain G2P[ 4 ] [ 63 ]. On the contrary, human neonate-specific rotavirus G10P[ 11 ] strains bind to both lacto-N-tetraose (LNT) and LNnT [ 62 ].…”