SARS-CoV-2 spike protein is a self-adjuvanted antigen for mucosal immunization and confers broad protection against lethal challenge with SARS-CoV-2 via intranasal vaccination

Research Square (Research Square), Journal Year: 2025, Volume and Issue: unknown

Published: March 19, 2025

Effective respiratory mucosal vaccines are urgently needed to control the rapid mutation and spread of SARS-CoV-2. In this respect, most focused virus vector-vaccine adjuvanted recombinant vaccine strategies face safety effectiveness concerns. Here, we revealed that spike protein (S-2P) original SARS-CoV-2 strain is a self-adjuvanted antigen for intranasal immunization can elicit potent systemic (serum IgG neutralizing antibodies splenic T-cell responses S1 S2 proteins) immunity (respiratory tract IgA responses) in absence an adjuvant. contrast, with hemagglutinin (HA) influenza H1N1 failed induce detectable serum antibodies. Furthermore, S-2P K18-hACE2 mice provided complete protection against lethal challenge 60% or 40% survival Omicron BA.5 EG.5, respectively. The immune induced by were significantly enhanced lentinan (LNT), immunomodulator used clinic, completely protected from EG.5 conferred additional protective mechanisms independent CD8 + T cells. Compared HA, robustly activated type I IFN signaling in vitro vivo, importantly, antibody response HA when it was simultaneously intranasally vaccinated HA. Mechanistically, integrins STING critically involved S-2P-eliciting via vaccination. Our findings demonstrate potential plus LNT as safe broad-spectrum variants.

Language: Английский

Long-term immune response after SARS-CoV2 vaccination in solid organ transplant recipients

BMC Infectious Diseases, Journal Year: 2025, Volume and Issue: 25(1)

Published: April 25, 2025

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccination in solid organ transplant (SOT) recipients is associated with suboptimal antibody response (AbR) favouring breakthrough infection (BI). The role of cell-mediated immunity (CMI) remains uncertain. Single-center prospective longitudinal cohort study adult SOT monitored for both AbR and CMI at 6 ± months after booster dosage SARS-CoV-2 vaccine. Primary end-point was BI diagnosis the main risk factor. Relationship between investigated by bivariate tests multivariable logistic regression. performed 139 patients. In 66 patients documented before CMI, thus 73 (33 kidney, 24 liver, 14 lung, heart) were analysed. first vaccine doses consisted BNT162b2 mRNA-1273 69.1% 30.9% cases, respectively. Whereas used as third dose 91.2% At a median 215 (IQR 181-252) days dose, 40 (54.8%) displayed 21 (28.8%) only 12 (16.4%) neither or CMI; there no showing negative positive CMI. Overall, 22 (30.1%) reported significant differences those vs. (59.1% 40.9%, p = 0.798), confirmed multiple regression adjusting age, type organs, high time from transplant. Our data suggest that population our cohort, does not appear to be strong predictor BI.

Language: Английский

Humoral and Cell-Mediated Immunity Against SARS-CoV-2 in Healthcare Personnel Who Received Multiple mRNA Vaccines: A 4-Year Observational Study

Infectious Disease Reports, Journal Year: 2025, Volume and Issue: 17(3), P. 42 - 42

Published: April 29, 2025

Background/Objectives: The long-term effects of multiple updated vaccinations against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have not been clarified. Humoral or cellular immunity dynamics in healthcare workers for four years were analyzed. Methods: Blood samples collected at five time points from April 2021 to January 2024. was analyzed using the 50% neutralizing titer (NT50) original Omicron XBB and BA.2.86 strains ELISpot interferon-gamma releasing assay. NT50s spot-forming count (SFC) assay compared SARS-CoV-2 XBB-, Omicron-infected, uninfected subjects. Results: 32 (median age, 47 years) who received 3–7 vaccine doses enrolled. strain decreased after second vaccination but maintained third dose. detected before introduced increased following vaccination. elevated natural infection by strain, albeit without differences with findings Multivariate regression analysis revealed no confounder that affected antibody fifth blood sampling. median number SFCs ranged 78 208 first two doses. Conclusions: Multiple induced production antibodies divergent activity emerging mutant enhanced protective strain. This finding supported importance

Language: Английский