Search

A mucosal route of vaccination could prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication at the site of infection and limit transmission. We compared protection against heterologous XBB.1.16 challenge in nonhuman primates (NHPs) ~5 months following intramuscular boosting with bivalent mRNA encoding WA1 and BA.5 spike proteins or mucosal boosting with a WA1-BA.5 bivalent chimpanzee adenoviral-vectored vaccine delivered by intranasal or aerosol device. NHPs boosted by either mucosal route had minimal virus replication in the nose and lungs, respectively. By contrast, protection by intramuscular mRNA was limited to the lower airways. The mucosally delivered vaccine elicited durable airway IgG and IgA responses and, unlike the intramuscular mRNA vaccine, induced spike-specific B cells in the lungs. IgG, IgA and T cell responses correlated with protection in the lungs, whereas mucosal IgA alone correlated with upper airway protection. This study highlights differential mucosal and serum correlates of protection and how mucosal vaccines can durably prevent infection against SARS-CoV-2., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

SARS-CoV-2 has the capacity to evolve mutations that escape vaccine- and infection-acquired immunity and antiviral drugs. A variant-agnostic therapeutic agent that protects against severe disease without putting selective pressure on the virus would thus be a valuable biomedical tool that would maintain its efficacy despite the ongoing emergence of new variants. Here, we challenge male rhesus macaques with SARS-CoV-2 Delta-the most pathogenic variant in a highly susceptible animal model. At the time of challenge, we also treat the macaques with aerosolized RBD-62, a protein developed through multiple rounds of in vitro evolution of SARS-CoV-2 RBD to acquire 1000-fold enhanced ACE2 binding affinity. RBD-62 treatment equivalently suppresses virus replication in both upper and lower airways, a phenomenon not previously observed with clinically approved vaccines. Importantly, RBD-62 does not block the development of virus-specific T- and B-cell responses and does not elicit anti-drug immunity. These data provide proof-of-concept that RBD-62 can prevent severe disease from a highly virulent variant., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

A systems analysis was conducted to determine the potential molecular mechanisms underlying differential immunogenicity and protective efficacy results of a clinical trial of the radiation-attenuated whole-sporozoite PfSPZ vaccine in African infants. Innate immune activation and myeloid signatures at prevaccination baseline correlated with protection from P. falciparum parasitemia in placebo controls. These same signatures were associated with susceptibility to parasitemia among infants who received the highest and most protective PfSPZ vaccine dose. Machine learning identified spliceosome, proteosome, and resting DC signatures as prevaccination features predictive of protection after highest-dose PfSPZ vaccination, whereas baseline circumsporozoite protein-specific (CSP-specific) IgG predicted nonprotection. Prevaccination innate inflammatory and myeloid signatures were associated with higher sporozoite-specific IgG Ab response but undetectable PfSPZ-specific CD8+ T cell responses after vaccination. Consistent with these human data, innate stimulation in vivo conferred protection against infection by sporozoite injection in malaria-naive mice while diminishing the CD8+ T cell response to radiation-attenuated sporozoites. These data suggest a dichotomous role of innate stimulation for malaria protection and induction of protective immunity by whole-sporozoite malaria vaccines. The uncoupling of vaccine-induced protective immunity achieved by Abs from more protective CD8+ T cell responses suggests that PfSPZ vaccine efficacy in malaria-endemic settings may be constrained by opposing antigen presentation pathways.

Purpose: The treatment of urethral stenosis after a combination of prostatectomy and radiation therapy for prostate cancer is understudied. We evaluate the clinical and patient-related outcomes after dorsal onlay buccal mucosal graft urethroplasty (D-BMGU) in men who underwent prostatectomy and radiation therapy., Materials and Methods: A multi-institutional, retrospective review of men with vesicourethral anastomotic stenosis or bulbomembranous urethral stricture disease after radical prostatectomy and radiation therapy from 8 institutions between 2013 to 2021 was performed. The primary outcomes were stenosis recurrence and development of de novo stress urinary incontinence. Secondary outcomes were surgical complications, changes in voiding, and patient-reported satisfaction., Results: Forty-five men were treated with D-BMGU for stenosis following prostatectomy and radiation. There was a total of 7 recurrences. Median follow-up in patients without recurrence was 21 months (IQR 12-24). There were no incidents of de novo incontinence, 28 patients were incontinent pre- and postoperatively, and of the 6 patients managed with suprapubic catheter preoperatively, 4 were continent after repair. Following repair, men had significant improvement in postvoid residual, uroflow, International Prostate Symptom Score, and International Prostate Symptom Score quality-of-life domain. Overall satisfaction was +2 or better in 86.6% of men on the Global Response Assessment., Conclusions: D-BMGU is a safe, feasible, and effective technique in patients with urethral stenosis after a combination of prostatectomy and radiation therapy. Although our findings suggest this technique may result in lower rates of de novo urinary incontinence compared to conventional urethral transection and excision techniques, head-to-head comparisons are needed.