The effect of preexisting neutralizing antibodies (NAb) on SARS-CoV-2 shedding in postvaccination infection (PVI) is not well understood. We characterized viral shedding longitudinally in nasal specimens in relation to baseline (pre/periinfection) serum NAb titers in 125 participants infected with SARS-CoV-2 variants. Among 68 vaccinated participants, we quantified the effect of baseline NAb titers on maximum viral RNA titers and infectivity duration. Baseline NAbs were higher and targeted a broader range of variants in participants with monovalent ancestral booster vaccinations compared with those with a primary vaccine series. In Delta infections, baseline NAb titers targeting Delta or Wuhan-Hu-1 correlated negatively with maximum viral RNA. Per log10 increase in Delta-targeting baseline NAb IC50, maximum viral load was reduced -2.43 (95% CI: -3.76, -1.11) log10 nucleocapsid copies, and infectious viral shedding was reduced -2.79 (95% CI: -4.99, -0.60) days. Conversely, in Omicron infections (BA.1, BA.2, BA.4, or BA.5), baseline NAb titers against Omicron lineages or Wuhan-Hu-1 did not predict viral outcomes. Our results provide robust estimates of the effect of baseline NAbs on the magnitude and duration of nasal viral replication after PVI (albeit with an unclear effect on transmission) and show how immune escape variants efficiently evade these modulating effects.
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http://dx.doi.org/10.1172/jci.insight.185953 | DOI Listing |
JCI Insight
March 2025
Department of Immunology and Microbiology, UCSF, San Francisco, California, USA.
The effect of preexisting neutralizing antibodies (NAb) on SARS-CoV-2 shedding in postvaccination infection (PVI) is not well understood. We characterized viral shedding longitudinally in nasal specimens in relation to baseline (pre/periinfection) serum NAb titers in 125 participants infected with SARS-CoV-2 variants. Among 68 vaccinated participants, we quantified the effect of baseline NAb titers on maximum viral RNA titers and infectivity duration.
View Article and Find Full Text PDFMol Ther
March 2025
Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Raymond G. Perelman Center for Cellular and Molecular Therapy, Children's Hospital of Philadelphia, Philadelphia, PA 19104; Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104. Electronic address:
Neutralizing antibodies (NAb) against adeno-associated virus (AAV) represent a significant obstacle to the efficacy of systemic recombinant AAV vector administration or re-administration. While there are some promising preclinical immunomodulation strategies in development, insights into which B cell subsets and compartments maintain persistent AAV NAb may define the optimal eradication strategy. Given the limited success of CD20-directed monotherapy in previous studies, we hypothesized that CD19-directed approaches that extend targeting into the plasma cell compartments may improve AAV NAb eradication.
View Article and Find Full Text PDFCancer Gene Ther
March 2025
Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
KD01, a third-generation conditionally replicating adenovirus serotype 5 developed by our team, has approved by the China Center for Drug Evaluation (CDE) for Phase I clinical trials (NCT06552598). However, 60% seroprevalence of anti-Ad5 neutralizing antibodies is a major hurdle for Ad5-based oncolytic viruses. To address this issue, we developed oAd5/35-HF, a fourth-generation oncolytic adenovirus vector designed to enhance infection efficiency and evade pre-existing neutralizing antibodies (NABs).
View Article and Find Full Text PDFVaccine
March 2025
Viral Vaccines R&D, Inventprise, Inc., Redmond, WA, USA. Electronic address:
The SARS-CoV-2 pandemic necessitated effective vaccines that can endure antigenic mutations. Here we demonstrate highly immunogenic conjugate vaccines that elicit broad cross-neutralization to variants of concern (VOC) in animal studies. By utilizing protein-protein conjugation and Toll-Like Receptor (TLR) agonist adjuvants we achieve enhanced immunogenicity compared to unconjugated equivalents.
View Article and Find Full Text PDFHum Gene Ther
February 2025
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Human Health and Services, Bethesda, Maryland, USA.
Niemann-Pick disease, type C1 (NPC1), is a rare, fatal neurodegenerative disorder caused by pathological variations in . We and others have previously demonstrated the efficacy of systemic adeno-associated virus (AAV) gene therapy with AAV9 in murine models of NPC1. The presence of neutralizing antibodies (NAbs) caused by natural exposure to wildtype AAVs may impair AAV transduction efficacy and reduce or negate the benefit of gene therapy.
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