Sign in Subscribe
COVID-19

Chronic Infections of SARS-CoV-2 May Evolve into Variants of Concern in Immunocompromised Individuals

Strategic Insights

— 1 min read

Researchers from Tel Aviv University have published a study in the journal Virus Evolution, revealing that chronic infections of SARS-CoV-2 in immunocompromised individuals can lead to the emergence of variants of concern (VOCs). The study, which focused on a cohort of nine immunocompromised patients with chronic infections, found that sequencing errors can lead to erroneous inference of genetic variation, and that a generalized linear model can be used to infer patient-specific non-synonymous divergence rates. The research suggests that intra-host viral evolution is shaped by variation in patient-specific selection pressures and within-host demographic histories.

Key Takeaways:

  • Chronic infections of SARS-CoV-2 in immunocompromised individuals can lead to the emergence of variants of concern (VOCs).
  • Sequencing errors can lead to erroneous inference of genetic variation.
  • A generalized linear model can be used to infer patient-specific non-synonymous divergence rates.
  • Intra-host viral evolution is shaped by variation in patient-specific selection pressures and within-host demographic histories.
  • The research was funded by Tel Aviv University, the Edmond J. Safra Center for Bioinformatics, and the Israeli Science Foundation.
  • The study focused on a cohort of nine immunocompromised patients with chronic infections.
  • The researchers used duplicate sequencing across patients and time points to distinguish errors from low-frequency mutations.

Statistics:

  • The study found a synonymous mutation rate of 1.9 x 10^-6 mutations/site/day.
  • Patient-specific non-synonymous divergence rates exhibited marked heterogeneity across individuals, ranging from 0.01 to 10 mutations/site/day.
  • The study identified episodes of high non-synonymous rates consistent with selective sweeps or subpopulation replacement.
  • The research used a generalized linear model that accounts for gradual mutation accumulation and episodic divergence shifts.

Sources:

  • Virus Evolution
  • Tel Aviv University
  • Edmond J. Safra Center for Bioinformatics
  • Israeli Science Foundation
  • Medical Letter on the CDC & FDA
  • NewsRx. Recent Research from Tel Aviv University Highlight Findings in COVID-19 (Diverse Patterns of Intra-host Genetic Diversity In Chronically Infected Sars-cov-2 Patients). Medical Letter on the CDC & FDA. August 10, 2025; p 129.

Read more