Background: The Omicron SARS-CoV-2 variant has spread internationally and is responsible for rapidly increasing case numbers. The emergence of divergent variants in the context of a heterogeneous and evolving neutralizing antibody response in host populations might compromise protection afforded by vaccines or prior infection.
Methods: We measured neutralizing antibody titers in 169 longitudinally collected plasma samples using pseudotypes bearing the Wuhan-hu-1 or the Omicron variant or a laboratory-designed neutralization-resistant SARS-CoV-2 spike (PMS20). Plasmas were obtained from convalescents who did or did not subsequently receive an mRNA vaccine, or naive individuals who received 3-doses of mRNA or 1-dose Ad26 vaccines. Samples were collected approximately 1, 5-6 and 12 months after initial vaccination or infection.
Results: Like PMS20, the Omicron spike protein was substantially resistant to neutralization compared to Wuhan-hu-1. In convalescent plasma the median deficit in neutralizing activity against PMS20 or Omicron was 30- to 60-fold. Plasmas from recipients of 2 mRNA vaccine doses were 30- to 180- fold less potent against PMS20 and Omicron than Wuhan-hu-1. Notably, previously infected or two-mRNA dose vaccinated individuals who received additional mRNA vaccine dose(s) had 38 to 154-fold and 35 to 214-fold increases in neutralizing activity against Omicron and PMS20 respectively.
Conclusions: Omicron exhibits similar distribution of sequence changes and neutralization resistance as does a laboratory-designed neutralization-resistant spike protein, suggesting natural evolutionary pressure to evade the human antibody response. Currently available mRNA vaccine boosters, that may promote antibody affinity maturation, significantly ameliorate SARS-CoV-2 neutralizing antibody titers.
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http://dx.doi.org/10.1101/2021.12.12.21267646 | DOI Listing |
Transplant Proc
January 2025
Gastroenterolgy and Hepatology Department, Group of Clinical and Translational Research in Liver Diseases, Research Institution Valdecilla (IDIVAL), University Hospital Marqués de Valdecilla, Santander, Spain. Electronic address:
Background: The Omicron variant of SARS-CoV-2 emerged as a new variant of concern, characterized by high transmissibility and lower severity compared with previous variants, and became the majority variant in the sixth wave in Spain. This study aims to assess the impact of SARS-CoV-2 infection on liver transplant recipients (LTRs) during 2023 in the population of Cantabria.
Methods: The study included 295 LTRs undergoing follow-up at the Liver Transplant Unit of the Marqués de Valdecilla University Hospital.
Trends Pharmacol Sci
January 2025
Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Parker Institute for Cancer Immunotherapy, University of California, Los Angeles, Los Angeles, CA 90095, USA. Electronic address:
Chimeric antigen receptor (CAR)-T cell therapy has transformed the treatment landscape for hematological cancers. However, achieving comparable success in solid tumors remains challenging. Factors contributing to these limitations include the scarcity of tumor-specific antigens (TSAs), insufficient CAR-T cell infiltration, and the immunosuppressive tumor microenvironment (TME).
View Article and Find Full Text PDFPoult Sci
January 2025
College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China. Electronic address:
To investigate the regulatory mechanism mediated by hypothalamic OPN5 on seasonal changes in the reproductive activities of domestic geese, 60 Magang ganders in their breeding period were selected for the experiment and evenly divided into an immunization group(OPN5-IM) and a control group. On days 0, 15 and 30, ganders in the immunized group were immunized with OPN5-KLH protein vaccine, and ganders in the control were immunized with the same amount of blank emulsified vaccine. Additionally, 120 female geese were provided to stimulate the reproductive activities of male geese.
View Article and Find Full Text PDFCell Rep
January 2025
Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA. Electronic address:
Virus neutralization profiles against primary infection sera and corresponding antigenic cartography are integral part of the COVID-19 and influenza vaccine strain selection processes. Human single variant exposure sera have previously defined the antigenic relationships among SARS-CoV-2 variants but are now largely unavailable due to widespread population immunity. Therefore, antigenic characterization of future SARS-CoV-2 variants will require an animal model, analogous to using ferrets for influenza virus.
View Article and Find Full Text PDFAs an advanced nucleic acid therapeutical modality, mRNA can express any type of protein in principle and thus holds great potential to prevent and treat various diseases. Despite the success in COVID-19 mRNA vaccines, direct local delivery of mRNA into the lung by inhalation would greatly reinforce the treatment of pulmonary pathogens and diseases. Herein, we developed lipid nanoparticles (LNPs) from degradable ionizable glycerolipids for potent pulmonary mRNA delivery via nebulization.
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