Genetic diversity and its impact on disease severity in respiratory syncytial virus subtype-A and -B bronchiolitis before and after pandemic restrictions in Rome

A Pierangeli; R Nenna; M Fracella; C Scagnolari; G Oliveto; L Sorrentino; F Frasca; M G Conti; L Petrarca; P Papoff; O Turriziani; G Antonelli; P Stefanelli; A T Palamara; F Midulla

doi:10.1016/j.jinf.2023.07.008

Genetic diversity and its impact on disease severity in respiratory syncytial virus subtype-A and -B bronchiolitis before and after pandemic restrictions in Rome

J Infect. 2023 Oct;87(4):305-314. doi: 10.1016/j.jinf.2023.07.008. Epub 2023 Jul 24.

Authors

A Pierangeli¹, R Nenna², M Fracella³, C Scagnolari⁴, G Oliveto⁵, L Sorrentino⁶, F Frasca⁷, M G Conti⁸, L Petrarca⁹, P Papoff¹⁰, O Turriziani¹¹, G Antonelli¹², P Stefanelli¹³, A T Palamara¹⁴, F Midulla¹⁵

Affiliations

¹ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: alessandra.pierangeli@uniroma1.it.
² Department of Pediatrics and Infantile Neuropsychiatry, Sapienza University, V.le Regina Elena, 299, 00161 Rome, Italy. Electronic address: raffaella.nenna@uniroma1.it.
³ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: matteo.fracella@uniroma1.it.
⁴ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: carolina.scagnolari@uniroma1.it.
⁵ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: giuseppe.oliveto@uniroma1.it.
⁶ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: leonardo.sorrentino@uniroma1.it.
⁷ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: federica.frasca@uniroma1.it.
⁸ Department of Pediatrics and Infantile Neuropsychiatry, Sapienza University, V.le Regina Elena, 299, 00161 Rome, Italy. Electronic address: mariagiulia.conti@uniroma1.it.
⁹ Department of Pediatrics and Infantile Neuropsychiatry, Sapienza University, V.le Regina Elena, 299, 00161 Rome, Italy. Electronic address: laura.petrarca@uniroma1.it.
¹⁰ Department of Pediatrics and Infantile Neuropsychiatry, Sapienza University, V.le Regina Elena, 299, 00161 Rome, Italy. Electronic address: paola.papoff@uniroma1.it.
¹¹ Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: ombretta.turriziani@uniroma1.it.
¹² Virology Laboratory, Department of Molecular Medicine, Sapienza University, V.le Porta Tiburtina, 28, 00185 Rome, Italy. Electronic address: guido.antonelli@uniroma1.it.
¹³ Department of Infectious Diseases, Istituto Superiore di Sanità, V.le Regina Elena, 299, 00161 Rome, Italy. Electronic address: paola.stefanelli@iss.it.
¹⁴ Department of Infectious Diseases, Istituto Superiore di Sanità, V.le Regina Elena, 299, 00161 Rome, Italy. Electronic address: annateresa.palamara@iss.it.
¹⁵ Department of Pediatrics and Infantile Neuropsychiatry, Sapienza University, V.le Regina Elena, 299, 00161 Rome, Italy. Electronic address: fabio.midulla@uniroma1.it.

PMID: 37495189
DOI: 10.1016/j.jinf.2023.07.008

Abstract

Objectives: To scrutinize whether the high circulation of respiratory syncytial virus (RSV) observed in 2021-2022 and 2022-2023 was due to viral diversity, we characterized RSV-A and -B strains causing bronchiolitis in Rome, before and after the COVID-19 pandemic.

Methods: RSV-positive samples, prospectively collected from infants hospitalized for bronchiolitis from 2017-2018 to 2022-2023, were sequenced in the G gene; phylogenetic results and amino acid substitutions were analyzed. Subtype-specific data were compared among seasons.

Results: Predominance of RSV-A and -B alternated in the pre-pandemic seasons; RSV-A dominated in 2021-2022 whereas RSV-B was predominant in 2022-2023. RSV-A sequences were ON1 genotype but quite distant from the ancestor; two divergent clades included sequences from pre- and post-pandemic seasons. Nearly all RSV-B were BA10 genotype; a divergent clade included only strains from 2021-2022 to 2022-2023. RSV-A cases had lower need of O₂ therapy and of intensive care during 2021-2022 with respect to all other seasons. RSV-B infected infants were more frequently admitted to intensive care units and needed O₂ in 2022-2023.

Conclusions: The intense RSV peak in 2021-2022, driven by RSV-A phylogenetically related to pre-pandemic strains is attributable to the immune debt created by pandemic restrictions. The RSV-B genetic divergence observed in post-pandemic strains may have increased the RSV-B specific immune debt, being a possible contributor to bronchiolitis severity in 2022-2023.

Keywords: Bronchiolitis severity; Genetic variability; Genotypes; Post-pandemic strains; Respiratory syncytial virus.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bronchiolitis* / epidemiology
COVID-19*
Genetic Variation
Genotype
Humans
Infant
Pandemics
Patient Acuity
Phylogeny
Respiratory Syncytial Virus Infections* / epidemiology
Respiratory Syncytial Virus, Human* / genetics
Rome / epidemiology