mRNA vaccines have shown high efficacy in preventing severe COVID-19, but breakthrough infections, emerging variants and waning antibody levels have warranted the use of boosters. Although mRNA boosters have been widely implemented, the extent to which pre-existing immunity influences the efficacy of boosters remains unclear. In a cohort of individuals primed with the mRNA-1273 or BNT162b2 vaccines, we observed that lower antibody levels before boost were associated with higher fold-increase in antibody levels after boost, suggesting that pre-existing antibody modulates the boosting capacity of mRNA vaccines. Mechanistic studies in mice show that pre-existing antibodies significantly limit antigen expression and priming of B cell responses after mRNA vaccination. Furthermore, we demonstrate that the relative superiority of an updated Omicron vaccine over the original vaccine is critically dependent on the serostatus of the host. These data demonstrate that pre-existing immunity dictates responses to mRNA vaccination, elucidating specific circumstances when updated SARS-CoV-2 vaccines confer superior protection to original vaccines.
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http://dx.doi.org/10.1101/2022.06.27.497248 | DOI Listing |
Nat Commun
January 2025
Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA.
The emergence of the Omicron lineage represented a major genetic drift in SARS-CoV-2 evolution. This was associated with phenotypic changes including evasion of pre-existing immunity and decreased disease severity. Continuous evolution within the Omicron lineage raised concerns of potential increased transmissibility and/or disease severity.
View Article and Find Full Text PDFCancers (Basel)
December 2024
Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milano, Italy.
Cancer immunotherapy, particularly immune checkpoint inhibitors, has positively impacted oncological treatments. Despite its effectiveness, immunotherapy is associated with immune-related adverse events (irAEs) that can affect any organ, including the liver. Hepatotoxicity primarily manifests as immune-related hepatitis and, less frequently, cholangitis.
View Article and Find Full Text PDFBMC Genomics
January 2025
Department of Animal Sciences, Purdue University, 270 S. Russell Street, West Lafayette, IN, 47907, USA.
Background: The profitability of the beef industry is directly influenced by the fertility rate and reproductive performance of both males and females, which can be improved through selective breeding. When performing genomic analyses, genetic markers located on the X chromosome have been commonly ignored despite the X chromosome being one of the largest chromosomes in the cattle genome. Therefore, the primary objectives of this study were to: (1) estimate variance components and genetic parameters for eighteen male and five female fertility and reproductive traits in Nellore cattle including X chromosome markers in the analyses; and (2) perform genome-wide association studies and functional genomic analyses to better understand the genetic background of male and female fertility and reproductive performance traits in Nellore cattle.
View Article and Find Full Text PDFBrain Commun
January 2025
Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
Persistent symptoms after COVID-19 constitute the long COVID syndrome, also called post-acute sequelae of SARS-CoV-2 infection (PASC). COVID-19 vaccines reduce the gravity of ensuing SARS-CoV-2 infections. However, whether vaccines also have an impact on PASC remain unknown.
View Article and Find Full Text PDFPLoS One
January 2025
Escuela de Salud Pública, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
Background: Most of the evidence on risk factors for COVID-19 complications comes from North America or Europe with very little research from Latin-America. We aimed to evaluate the association between sociodemographic, clinical factors and the risk of COVID-19 complications among adults in Chile, the fifth Latin-American country with more COVID-19 reported cases since de beginning of the Pandemic.
Methods: A retrospective population-based cohort study using data from electronic health records from a large Primary Care Network, linked to national hospital, immunization, Covid-19 PCR surveillance, mortality and birth records.
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