medRxiv
Published: December 2022
Waning immunity to vaccination represents a major challenge in vaccinology. Whether booster vaccination improves the durability of immune responses is unknown. Here we show, using a cohort of 55 adult vaccinees who received the BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccine against SARS-CoV-2, that a booster (i.e., 3 immunization) dose at 6 - 10 months increased the half-life of serum neutralizing antibody (nAb) titers to 76 days from 56 - 66 days estimated after the primary two-dose vaccination series. A second booster dose (i.e., 4 immunization) more than a year after the primary vaccination increased the half-life further to 88 days. However, despite this modestly improved durability in nAb responses against the Wuhan strain, there was a loss in neutralization capacity against Omicron subvariants, especially the recently emerged variants, BA.2.75.2 and BQ.1.1 (35 and 50-fold drop in titers respectively, relative to the ancestral (WA.1) strain. While only 55 â€" 65% of participants demonstrated a detectable nAb titer against the newer variants after the booster (3 dose), the response declined to below the detection limit in almost all individuals by 6 months. Notably, even against BA.1 and BA.5, the titers declined rapidly in a third of the vaccinees and were below the detection limit at 6 months. In contrast, booster vaccination induced antigen-specific memory B and T cells that persisted for at least 6 months. Collectively, our data show that the durability of immune responses improves following subsequent booster immunizations; however, the emergence of immune evasive variants reduces the effectiveness of booster doses in preventing infection.
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http://dx.doi.org/10.1101/2022.12.02.22282921 | DOI Listing |
Chin Clin Oncol
December 2024
Colorectal Cancer Center, Sichuan University West China Hospital, Chengdu, China; Department of Medical Oncology, Cancer Center, Sichuan University West China Hospital, Chengdu, China.
Background: Epstein-Barr virus-associated gastric cancer (EBVaGC) is characterized by higher lymphocytic infiltration, which predicts sensitivity to immunotherapy. However, there are few studies investigating the mechanisms of acquired resistance to programmed cell death protein 1 (PD-1) blockade and its subsequent treatment strategies for EBVaGC.
Case Description: We describe the case of a patient with EBVaGC who was initially treated with first-line chemotherapy plus Sintilimab, a fully humanized anti-PD-1 monoclonal antibody, resulting in a near-complete response.
J Transl Med
January 2025
Department of Medical Oncology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Anhui Provincial Cancer Hospital, Hefei, 230031, Anhui, China.
Background: Agonistic monoclonal antibodies targeting 4-1BB/CD137 have shown preclinical promise, but their clinical development has been limited by severe liver toxicity or limited efficacy. Therefore, a safe and efficient immunostimulatory molecule is urgently needed for cancer immunotherapy.
Methods: A novel anti-MSLN×4-1BB bispecific antibody (bsAb) was generated via antibody engineering, and its affinity and activity were detected via enzyme-linked immunosorbent assay (ELISA), flow cytometry, and T-cell activation and luciferase reporter assays.
Lancet Microbe
December 2024
Jenner Institute, University of Oxford-NIHR Oxford Biomedical Research Centre, Oxford, UK. Electronic address:
Background: Malaria remains a substantial public health burden among young children in sub-Saharan Africa and a highly efficacious vaccine eliciting a durable immune response would be a useful tool for controlling malaria. R21 is a malaria vaccine comprising nanoparticles, formed from a circumsporozoite protein and hepatitis B surface antigen (HBsAg) fusion protein, without any unfused HBsAg, and is administered with the saponin-based Matrix-M adjuvant. This study aimed to assess the safety and immunogenicity of the malaria vaccine candidate, R21, administered with or without adjuvant Matrix-M in adults naïve to malaria infection and in healthy adults from malaria endemic areas.
View Article and Find Full Text PDFBiomaterials
January 2025
School of Life Science, Chongqing University, Chongqing, 400044, China. Electronic address:
In-situ tumor vaccination remains challenging due to difficulties in the exposure and presentation of tumor-associated neoantigens (TANs). In view of the central role of lipid metabolism in cell fate determination and tumor-immune cell communication, here we report a photo-controlled lipid metabolism nanoregulator (PLMN) to achieve robust in-situ adjuvant-free vaccination, which is constructed through hierarchically integrating photothermal-inducible arachidonate 15-lipoxygenase (ALOX15)-expressing plasmids, cypate and FIN56 into cationic liposomes. Near-infrared light (NIR) stimulation triggers on-demand ALOX15 editing and causes excessive accumulation of downstream pro-ferroptosis lipid metabolites.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
SKKU Advanced Institute of Nanotechnology (SAINT), Department of Nano Engineering, Department of Nano Science and Technology, School of Chemical Engineering, Biomedical Institute for Convergence at SKKU, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea.
Despite their safety and widespread use, conventional protein antigen-based subunit vaccines face significant challenges such as low immunogenicity, insufficient long-term immunity, poor CD8 T-cell activation, and poor adaptation to viral variants. To address these issues, an infection-mimicking gel (IM-Gel) is developed that is designed to emulate the spatiotemporal dynamics of immune stimulation in acute viral infections through in situ supramolecular self-assembly of nanoparticulate-TLR7/8a (NP-TLR7/8a) and an antigen with tannic acid (TA). Through collagen-binding properties of TA, the IM-Gel enables sustained delivery and enhanced retention of NP-TLR7/8a and protein antigen in the lymph node subcapsular sinus of mice for over 7 days, prolonging the exposure of vaccine components in both B cell and T cell zones, leading to robust humoral and cellular responses.
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