The molecular epidemiology of respiratory syncytial virus in Ontario, Canada from 2022-2024 using a custom whole genome sequencing assay and analytics package.

Background: Respiratory Syncytial Virus (RSV) infections are a cause of significant morbidity and mortality in children and the elderly. Despite the clinical burden of disease, very little is known about the inter- and intra-seasonal genomic variability of RSV. Furthermore, the recent approval of vaccines and monoclonal antibody therapies will likely lead to higher selective pressure on RSV.

Prevalence of Low-Frequency, Antiviral Resistance Variants in SARS-CoV-2 Isolates in Ontario, Canada, 2020-2023.

Importance: Nirmatrelvir-ritonavir is an oral antiviral medication that improves outcomes in SARS-CoV-2 infections. However, there is concern that antiviral resistance will develop and that these viruses could be selected for after treatment.

Objective: To determine the prevalence of low-frequency SARS-CoV-2 variants in patient samples that could be selected for by nirmatrelvir-ritonavir.

Comparison of SARS-CoV-2 Viral Loads in the Nasal Mucosa of Patients Infected With BA.1, BA.2, or BA.5 Omicron Lineages.

Lower viral loads were observed in the upper respiratory tract of patients infected with BA.1, whereas patients infected with BA.2 and BA.