Background: The pathological and physiological characteristics between HBsAg-positive HBV infection and occult hepatitis B infection (OBI) are currently unclear. This study aimed to explore the immune microenvironment in the peripheral circulation of OBI patients through integration of proteomic and metabolomic sequencing, and to identify molecular biomarkers for clinical diagnosis of HBsAg-positive HBV and OBI.Methods: This research involved collection of plasma from 20 patients with OBI (negative for HBsAg but positive for HBV DNA, with HBV DNA levels < 200 IU/mL), 20 patients with HBsAg-positive HBV infection, and 10 healthy individuals. Mass spectrometry-based detection was used to analyze the proteome, while nuclear magnetic resonance spectroscopy was employed to study the metabolomic phenotypes. Differential molecule analysis, pathway enrichment and functional annotation, as well as weighted correlation network analysis (WGCNA), were conducted to uncover the characteristics of HBV-related liver disease. Prognostic biomarkers were identified using machine learning algorithms, and their validity was confirmed in a larger cohort using enzyme linked immunosorbent assay (ELISA).Results: HBsAg-positive HBV individuals showed higher ALT levels (p=0.010) when compared to OBI patients. The influence of HBV infection on metabolic functions and inflammation was evident through the analysis of distinct metabolic pathways in HBsAg-positive HBV and OBI groups. Tissue tracing demonstrated a connection between Kupffer cells and HBsAg-positive HBV infection, as well as between hepatocytes and OBI. Immune profiling revealed the correlation between CD4 Tem cells, memory B cells and OBI, enabling a rapid response to infection reactivation through cytokine secretion and antibody production. A machine learning-constructed and significantly expressed molecule-based diagnostic model effectively differentiated HBsAg-positive and OBI groups (AUC values > 0.8). ELISA assay confirmed the elevation of FGB and FGG in OBI samples, suggesting their potential as biomarkers for distinguishing OBI from HBsAg-positive infection.Conclusions: The immune microenvironment and metabolic status of HBsAg-positive HBV patients and OBI patients vary significantly. The machine learning-based diagnostic model described herein displayed impressive classification accuracy, presenting a non-invasive means of differentiating between OBI and HBsAg-positive HBV infections.

Coronavirus disease 2019 (COVID-19) has ravaged the world since December 2019. Up to now, it is still prevalent around the world. Vaccines are an important means to prevent the spread of COVID-19 and reduce severe disease and mortality. Currently, different types of novel coronavirus vaccines are still being developed and improved, and the relevant vaccines that have been approved for marketing have been widely vaccinated around the world. As vaccination coverage continues to grow, concerns about the efficacy and safety of vaccines after real-world use have grown. Some clinical studies have shown that vaccine effectiveness is closely related to antibody response after vaccination. Among them, the advantages of COVID-19 messenger ribonucleic acid (mRNA) vaccine, such as better adaptability to variant strains and better immune response ability, have attracted great attention. However, different populations with different genders, ages, previous COVID-19 infection history, underlying diseases and treatments will show different antibody responses after mRNA vaccination, which will affect the protection of the vaccine. Based on this, this paper reviews the reports related severe acute respiratory syndrome Coronavirus 2 mRNA vaccines, and summarizes the effectiveness of vaccines in different populations and different disease states and looked forward to the precise vaccination strategy of the vaccine in the future.

Introduction: Fulminant myocarditis is a life-threatening disease among young patients. Pseudomonas aeruginosa is distributed in nature and is often spread as an opportunistic pathogen to cause hospital-acquired infections in patients with underlying diseases and low immunity. Case Presentation: This report presented a case of a 28-year-old woman with fulminant myocarditis followed by P. aeruginosa infection. After hospitalization, she received veno-arterial extracorporeal membrane oxygenation (ECMO) and continuous renal replacement treatment (CRRT). Initially, piperacillin sodium tazobactam combined with amikacin was used for anti-infection therapy, which had a poor clinical effect. Subsequently, it was recommended to use ceftazidime-avibactam and amikacin for treatment. Finally, the infection index of the patient returned to normal. Conclusions: It is necessary to select correct and effective drugs according to etiology, considering the influence of ECMO and CRRT on the patient’s antimicrobial pharmacokinetics/pharmacodynamics (PK/PD). This case could provide a reference for safe and rational drug use in clinical practice.

Introduction: Vibrio vulnificus is a pathogen that usually induces serious infections and even life-threatening diseases. It might delay the diagnosis and targeted treatment of V. vulnificus infection due to early atypical symptoms and low incidence. Case Presentation: A 73-year-old woman with cerebral infarction developed necrotizing fasciitis with septic infection after admission. The patient developed rapidly progressive symptoms of the right lower limb, nausea and vomiting, hypotension, and liver and kidney function insufficiency on day 10 of hospitalization. Laboratory tests showed a significant increase in infection indicators, and blood cultures showed V. vulnificus growth. Early anti-infective drugs showed a gradual decline in the infection indexes but an aggravation trend in the right lower extremity lesions. The antibiotic regimen was adjusted to cephalosporin combined with quinolones, and local incision decompression and drainage were performed. The patient's infection was controlled, and the local lesion shrank. Conclusions: This case report suggests the importance of referring to the results of drug sensitivity and choosing proper antibiotics in consideration of various factors, such as the infected site of the patient and pharmacokinetics/pharmacodynamics (PK/PD) characteristics of antibiotics for V. vulnificus infection. Meanwhile, the timing of surgical intervention is also crucial for the necrotizing fasciitis caused by V. vulnificus.