ArticleEmerging microbes & infections2022
SARS-CoV-2 Omicron variant shows less efficient replication and fusion activity when compared with Delta variant in TMPRSS2-expressed cells.
Article in Emerging microbes & infections, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 262 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
262 citing papers in PubMed, 2 syntheses or guidelines pooled it, 473 citations in OpenAlex.
- Serial cycle threshold to assess the infectious potential of SARS-CoV-2: A systematic review.Epidemiology and infection · 2026Pooled it
- Association of Infection with Different SARS-CoV-2 Variants during Pregnancy with Maternal and Perinatal Outcomes: A Systematic Review and Meta-Analysis.International journal of environmental research and public health · 2022Pooled it
- Loss-of-function mutation in Omicron variants reduces spike protein expression and attenuates SARS-CoV-2 infection.Nature communications · 2026Article
- Immune evasion, infectivity, and membrane fusion of SARS-CoV-2 variants LP.8.1.1, XEC.25.1, XFG, and NB.1.8.1.Microbiology spectrum · 2026Article
- Article
- Omicron infection alters the profile of organ failure in severe COVID-19: a multicenter study comparing Omicron and the wild-type strain.BMC infectious diseases · 2026Observational
- IFITM3 deficiency drives SARS-CoV-2 adaptation while preserving variant-specific traits.Nature communications · 2026Article
- K5 polysaccharides inhibit SARS-CoV-2 infection by preventing spike-proteolytic priming.Npj viruses · 2026Article
- Evolution and viral properties of the SARS-CoV-2 BA.3.2 subvariant.Virus evolution · 2026Article
- Vacuolar-ATPase inhibitors are antimicrobial agents active against intracellular mycobacteria.Antimicrobial agents and chemotherapy · 2025Article
- Genomic and epidemiological characterization of SARS-CoV-2 in Northeastern Brazil: a comprehensive analysis (2020-2024).Archives of virology · 2025Article
- Selective Endocytosis-Mediated Omicron S1-RBD Internalization Revealed by Reconstitution of ACE2-S1-RBD Interaction on Micropatterned Membrane Substrates.International journal of molecular sciences · 2025Article
- Enhanced bafilomycin A1 production in Streptomyces Griseobrunneus via protoplast fusion combined with high-throughput screening.World journal of microbiology & biotechnology · 2025Article
- What Has SARS-CoV-2 Taught Us About Evolution?Cureus · 2025Review
- Evolution of the SARS-CoV-2 spike protein in utilizing host transmembrane serine proteases.iScience · 2025Article
- Article
- Article
- SARS-CoV-2 spike protein: structure, viral entry and variants.Nature reviews. Microbiology · 2025Review
- Immune evasion, infectivity, and membrane fusion of the SARS-CoV-2 JN.1 variant.Virology journal · 2025Article
- Receptor Binding for the Entry Mechanisms of SARS-CoV-2: Insights from the Original Strain and Emerging Variants.Viruses · 2025Review
202 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
14 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The novel SARS-CoV-2 Omicron variant (B.1.1.529), first found in early November 2021, has sparked considerable global concern and it has >50 mutations, many of which are known to affect transmissibility or cause immune escape. In this study, we sought to investigate the virological characteristics of the Omicron variant and compared it with the Delta variant which has dominated the world since mid-2021. Omicron variant replicated more slowly than the Delta variant in transmembrane serine protease 2 (TMPRSS2)-overexpressing VeroE6 (VeroE6/TMPRSS2) cells. Notably, the Delta variant replicated well in Calu3 cell line which has robust TMPRSS2 expression, while the Omicron variant replicated poorly in this cell line. Competition assay showed that Delta variant outcompeted Omicron variant in VeroE6/TMPRSS2 and Calu3 cells. To confirm the difference in entry pathway between the Omicron and Delta variants, we assessed the antiviral effect of bafilomycin A1, chloroquine (inhibiting endocytic pathway), and camostat (inhibiting TMPRSS2 pathway). Camostat potently inhibited the Delta variant but not the Omicron variant, while bafilomycin A1 and chloroquine could inhibit both Omicron and Delta variants. Moreover, the Omicron variant also showed weaker cell-cell fusion activity when compared with Delta variant in VeroE6/TMPRSS2 cells. Collectively, our results suggest that Omicron variant infection is not enhanced by TMPRSS2 but is largely mediated via the endocytic pathway. The difference in entry pathway between Omicron and Delta variants may have an implication on the clinical manifestations or disease severity.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.