Emerging in November 2021, the SARS-CoV-2 Omicron variant of concern exhibited marked immune evasion resulting in reduced vaccine effectiveness against SARS-CoV-2 infection and symptomatic disease. Most vaccine effectiveness data on Omicron are derived from the first Omicron subvariant, BA.1, which caused large waves of infection in many parts of the world within a short period of time. BA.1, however, was replaced by BA.2 within months, and later by BA.4 and BA.5 (BA.4/5). These later Omicron subvariants exhibited additional mutations in the spike protein of the virus, leading to speculation that they might result in even lower vaccine effectiveness. To address this question, the World Health Organization hosted a virtual meeting on December 6, 2022, to review available evidence for vaccine effectiveness against the major Omicron subvariants up to that date. Data were presented from South Africa, the United Kingdom, the United States, and Canada, as well as the results of a review and meta-regression of studies that evaluated the duration of the vaccine effectiveness for multiple Omicron subvariants. Despite heterogeneity of results and wide confidence intervals in some studies, the majority of studies showed vaccine effectiveness tended to be lower against BA.2 and especially against BA.4/5, compared to BA.1, with perhaps faster waning against severe disease caused by BA.4/5 after a booster dose. The interpretation of these results was discussed and both immunological factors (i.e., more immune escape with BA.4/5) and methodological issues (e.g., biases related to differences in the timing of subvariant circulation) were possible explanations for the findings. COVID-19 vaccines still provide some protection against infection and symptomatic disease from all Omicron subvariants for at least several months, with greater and more durable protection against severe disease.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9910025 | PMC |
http://dx.doi.org/10.1016/j.vaccine.2023.02.020 | DOI Listing |
Microb Biotechnol
January 2025
Department of Animal Biotechnology, Dankook University, Cheonan, Korea.
The coronavirus disease 2019 (COVID-19) is a fatal disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). To date, several vaccines have been developed to combat the spread of this virus. Mucosal vaccines using food-grade bacteria, such as Lactobacillus spp.
View Article and Find Full Text PDFMolecules
December 2024
Laboratory of Veterinary Microbiology, Joint Graduate School of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8511, Japan.
No effective vaccines or treatments are currently available for severe fever with thrombocytopenia syndrome (SFTS), a fatal tick-borne infectious disease caused by the SFTS virus (SFTSV). This study evaluated the potential of In-labeled anti-SFTSV antibodies targeting SFTSV structural proteins as single-photon emission computed tomography (SPECT) imaging agents for the selective visualization of SFTSV-infected sites. This study used nuclear medicine imaging to elucidate the pathology of SFTS and assess its therapeutic efficacy.
View Article and Find Full Text PDFBMC Infect Dis
January 2025
Patient-Centered Research, Evidera, London, UK.
Background: Seasonal vaccination is the mainstay of human influenza prevention. Licensed influenza vaccines are regularly updated to account for viral mutations and antigenic drift and are standardised for their haemagglutinin content. However, vaccine effectiveness remains suboptimal.
View Article and Find Full Text PDFAnaerobe
January 2025
Centro de Desenvolvimento Tecnológico, Biotecnologia, Universidade Federal de Pelotas, Rio Grande do Sul, Brasil.
Paeniclostridium sordellii is responsible for severe infections in horses, cattle, and sheep; however, conventional vaccines exhibit limitations in production and immunogenicity. This study assessed the immunogenicity of a recombinant bacterin composed of a chimera (rQTcsHL) that combines segments from the lethal (TcsL) and hemorrhagic (TcsH) toxins in mice and sheep. Both immunized animal groups exhibited elevated levels of IgG, with the mice demonstrating moderate protection (<50%) against lethal challenges, comparable to that of the conventional vaccine.
View Article and Find Full Text PDFVet Microbiol
January 2025
Department of Agricultural and Environmental Sciences, College of Agriculture, Tennessee State University, Nashville, TN, United States. Electronic address:
Porcine reproductive and respiratory syndrome (PRRS), caused by the highly variable PRRS virus (PRRSV), presents a significant challenge to the swine industry due to its pathogenic and economic burden. The virus evades host immune responses, particularly interferon (IFN) signaling, through various viral mechanisms. Traditional vaccines have shown variable efficacy in the field, prompting the exploration of novel vaccination strategies.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!