Newly Isolated SARS-CoV-2 Strain from Pediatric Patient Offers Key Insights into Viral Evolution & Treatment
SEOUL, SOUTH KOREA – Researchers have successfully isolated a unique strain of SARS-CoV-2, designated N15, from a pediatric COVID-19 patient, providing a valuable resource for understanding viral diversity and assessing the effectiveness of antiviral therapies. The findings, published today, highlight the importance of studying viral isolates from children, a population historically underrepresented in genomic surveillance efforts.
Despite the global decline in severe COVID-19 cases, SARS-CoV-2 continues to evolve, necessitating ongoing research to track emerging variants and optimize treatment strategies. Pediatric cases, while often milder, contribute to the virus’s transmission and potential for mutation. This newly isolated strain, originating from a nasal swab sample, offers a crucial reference point for comparative analyses against currently circulating variants and for evaluating the efficacy of existing and novel antiviral drugs.
The research team employed vero cells to isolate the virus through five passages of blind culture. Replication was confirmed via digital RT-PCR and visually observed through microscopic examination of cytopathic effects - the appearance of clusters of dead cells – within 48 hours of infection. Subsequent next-generation sequencing revealed N15 to be classified within the 19B lineage,exhibiting 99.9% genomic similarity to the original Wuhan-Hu-1 strain.
Notably, the N15 isolate harbored two rare mutations: N709S in the spike protein and T11M in the E protein. despite these mutations, the virus demonstrated replication kinetics comparable to the B.1 and B.1.1.529 (Omicron) lineages.
Antiviral testing indicated that Remdesivir, Molnupiravir, and Nirmatrelvir all effectively inhibited N15 replication, though IC50 values varied depending on the cell type used in the assays. Researchers emphasize that the isolate’s sensitivity to these treatments underscores its potential as a benchmark for evaluating antiviral efficacy against future variants.
The N15 strain, with its blend of ancestral genomic features and unique mutations, represents a meaningful addition to the growing catalog of SARS-CoV-2 isolates. Its availability will facilitate ongoing research aimed at unraveling the complexities of viral evolution and informing public health responses to the ongoing pandemic.
Keywords: N15 strain; SARS-CoV-2; biology; genetic characterization; pediatric patient.