Objectives: We aimed to quantify how the vaccine efficacy of BNT162b2, messenger RNA-1273, AD26.COV2-S, and ChAdOx1 nCoV-19 against detected infection by the SARS-CoV-2 Delta and Omicron variants varied by time since the last dose, vaccine scheme, age, and geographic areas.
Methods: We analyzed 3,261,749 community polymerase chain reaction tests conducted by private laboratories in France from December 2021 to March 2022 with a test-negative design comparing vaccinated to unvaccinated individuals.
Results: Efficacy against detected infection by Delta was 89% (95% confidence interval, 86-91%) at 2 weeks, down to 59% (56-61%) at 26 weeks and more after the second dose. Efficacy against Omicron was 48% (45-51%) at 2 weeks, down to 4% (2-5%) at 16 weeks after the second dose. A third dose temporarily restored efficacy. Efficacy against Omicron was lower in children and the elderly. Geographical variability in efficacy may reflect variability in the ratio of the number of contacts of vaccinated vs unvaccinated individuals. This ratio ranged from 0 to +50% across departments and correlated with the number of restaurants and bars per inhabitant (beta = 15.0 [0.75-29], P-value = 0.04), places that only vaccinated individuals could access in the study period.
Conclusion: SARS-CoV-2 vaccines conferred low and transient protection against Omicron infection.
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http://dx.doi.org/10.1016/j.ijid.2023.04.410 | DOI Listing |
J Infect Dis
January 2025
Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland 21218, USA.
Clinical trials that employ human challenge, also known as controlled human infection models (CHIM), have rapidly advanced vaccine development for multiple pathogens, including at least 30 disease models to date. CHIM studies, championed by networks of researchers, regulators, ethicists, technical experts, and other stakeholders, limit exposure of individuals to an investigational product, de-risk product investments, identify correlates of protection, and most importantly provide a prompt readout of vaccine efficacy. While CHIM studies provide multiple advantages, important challenges exist, including strengthening the relevance and comparability of CHIM study results to efficacy trials in endemic areas, particularly in resource-limited settings.
View Article and Find Full Text PDFClin Infect Dis
January 2025
GSK, Wavre, Belgium.
Background: In this phase 3 trial of an investigational maternal respiratory syncytial virus prefusion F protein-based vaccine (RSVPreF3-Mat), a higher rate of preterm birth was observed in the vaccine (6.8%) versus the placebo group (4.9%).
View Article and Find Full Text PDFmSphere
January 2025
Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA.
Malaria is a highly lethal infectious disease caused by parasites. These parasites are transmitted to vertebrate hosts when mosquitoes of the genus probe for a blood meal. Sporozoites, the infectious stage of , transit to the liver within hours of injection into the dermis.
View Article and Find Full Text PDFGerontologist
January 2025
Population Health Initiative, University of Washington, Seattle, WA, USA.
Background And Objectives: The study aimed to identify key drivers of vaccine hesitancy among healthcare workers (HCWs) employed at Long-term care facilities (LTCF) within selected states. It also sought to determine which interventions, policies, and programs effectively reduced HCW vaccine hesitancy for COVID-19 and influenza.
Research Design And Methods: The study employed a mixed methods approach, combining secondary analysis of the Behavioral Risk Factor Surveillance System (BRFSS) data, survey research, and focus groups.
Angew Chem Int Ed Engl
January 2025
University of Science and Technology of China School of Biomedical Engineering, Department of Polymer Science and Engineering, 96 Jinzhai Road, 230026, Hefei, CHINA.
Lipid nanoparticles (LNPs) based messenger RNA (mRNA) therapeutics hold immense promise for treating a wide array of diseases, while their nonhepatic organs targeting and insufficient endosomal escape efficiency remain challenges. For LNPs, polyethylene glycol (PEG) lipids have a crucial role in stabilizing them in aqueous medium, but they severely hinder cellular uptake and reduce transfection efficiency. In this study, we designed ultrasound (US)-assisted fluorinated PEGylated LNPs (F-LNPs) to enhance spleen-targeted mRNA delivery and transfection.
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