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: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2), has resulted in 777 million cases worldwide. Various vaccines have been approved to control the spread of COVID-19, with mRNA vaccines (Pfizer and Moderna) being widely used in the USA. We conducted a prospective longitudinal study to analyze the immune response elicited by two/three and four doses of monovalent mRNA vaccines in both vaccinated individuals and those who experienced breakthrough infections. Participants were stratified into different age groups: 18-40, 41-60, and over 60 years. : We assessed cross-variant neutralization responses in two cohorts-Cohort I: n = 167 (serum), Cohort II: n = 92 (serum and nasal swab) samples-using infectious virus microneutralization assay (MN) and antibody (IgG or IgA) binding ELISA titers to the spike protein receptor binding domain (RBD). Samples were collected from the Louisville Metro-Jefferson County Co-Immunity Project, a federally funded, population-based study for the surveillance of SARS-CoV-2 in Jefferson County, Kentucky during 2020-2022, involving both health care workers and a local community. : Individuals who received two doses of the mRNA vaccine exhibited reduced neutralization against Beta, Delta, and Omicron BA.1 variants compared to wildtype Wuhan, with further decline observed six months post-booster vaccination. However, individuals who experienced natural COVID-19 infection (breakthrough) after receiving two vaccine doses showed enhanced neutralization and antibody responses, particularly against Omicron BA.1. Following the 3rd dose, antibodies and neutralization responses were restored. Among triple-vaccinated individuals, reduced neutralization was observed against Omicron variants BA.1, BA.5, and BA.2 compared to Wuhan. Neutralization responses were better against BA.2 variant compared to BA.1 and BA.5. However, individuals who received three doses of vaccine and experienced a breakthrough infection (n = 45) elicited significantly higher neutralizing antibodies responses against all Omicron subvariants compared to vaccinated individuals. Interestingly, nasal swab samples collected from volunteers with breakthrough infection showed significantly elevated spike-reactive mucosal IgA antibodies and enhanced cross neutralization against BA.1, BA.2, and BA.5 compared to individuals who received only three vaccine doses. : mRNA vaccination elicits a strong systemic immune response by boosting serum neutralizing antibodies (NAb), although this protection wanes over time, allowing new variants to escape neutralization. Breakthrough individuals have extra enrichment in nasal NAb offering protection against emerging variants. This longitudinal immune profiling underscores the strengthening of pandemic preparedness and supports the development of durable mucosal vaccines against respiratory infectious disease.
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http://dx.doi.org/10.3390/vaccines13060559 | DOI Listing |
AAPS J
September 2025
Gene Transfer and Immunogenicity Branch, Division of Gene Therapy 2, Office of Gene Therapy, Office of Therapeutic Products, Center for Biologics Evaluation and Research, US Food and Drug Administration, WO52 RM3124, 10903 New Hampshire Ave, Silver Spring, Maryland, 20993-0002, USA.
As the field of gene therapy advances and as the importance of sex as a biological variable in shaping viral immune responses is recognized, the impact of sex on adeno-associated virus (AAV) vectors mediated gene therapies remain largely unexplored. Here we review current understanding of the immune response against AAV gene therapy as well as the knowledge of sex differences observed in viral responses. We discuss sex differences in innate immune mechanisms such as Toll-like receptor recognition and complement activation, as well as the functional responses of key immune cells such as dendritic cells, macrophages, and T/B cells that are involved in AAV immunogenicity.
View Article and Find Full Text PDFVet Microbiol
September 2025
College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang 471023, PR China; Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Henan University of Science and Techno
Bovine Viral Diarrhea Virus (BVDV) is a major pathogen associated with calf diarrhea and reproductive disorders in cattle. This study evaluated the immune-protective potential of a subunit vaccine based on the capsid C protein of the BVDV HNL-1 strain. In mice model, the C protein subunit vaccine exhibits a favorable safety and elicits robust immune-protective efficacy comparable to commercial inactivated vaccines.
View Article and Find Full Text PDFSci Adv
September 2025
The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA.
Influenza A viruses remain a global health threat, yet no universal antibody therapy exists. Clinical programs have centered on neutralizing mAbs, only to be thwarted by strain specificity and rapid viral escape. We instead engineered three non-neutralizing IgG2a mAbs that target distinct, overlapping epitopes within the conserved N terminus of the M2 ectodomain (M2e).
View Article and Find Full Text PDFSci Transl Med
September 2025
Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Human B cell immunity to the influenza hemagglutinin (HA) stem, a universal vaccine target, is often stereotyped and immunogenetically restricted, posing hurdles to study outside of humans. Here, we show that cynomolgus macaques vaccinated with an HA stem immunogen elicit humanlike public B cell lineages targeting two major conserved sites of vulnerability, the central stem and anchor epitopes. Central stem antibodies were predominantly derived from V1-138, the macaque homolog of human V1-69, a V gene preferentially used in human central stem broadly neutralizing antibodies (bnAbs).
View Article and Find Full Text PDFNatl Sci Rev
September 2025
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou 215123, China.
Chimeric antigen receptor T (CAR-T)-cell therapy is a promising resolution for solid tumors, but its corresponding clinical translation has been hindered by unsatisfactory therapeutic potency and severe cytokine release syndrome. Herein, tetracycline (Tet)-On inducible human epidermal growth factor receptor 1 (HER1)-targeted CAR-T (Tet-HER1-CAR-T) cells were engineered to enable spatially selective activation at tumor sites by doxycycline (Doxy), which is delivered by pH-responsive stealth liposomal calcium carbonate nanoparticles (Doxy@CaCO-PEG). Compared with the intravenous administration of conventional HER1-CAR-T cells and Tet-HER1-CAR-T cells activated by free Doxy, concurrent intravenous administration of Tet-HER1-CAR-T cells and Doxy@CaCO-PEG leads to the localized tumor activation of Tet-HER1-CAR-T cells and reduced systemic secretion of inflammatory cytokines.
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