Safety and immunogenicity of a live recombinant Newcastle disease virus-based COVID-19 vaccine (Patria) administered via the intramuscular or intranasal route: Interim results of a non-randomized open label phase I trial in Mexico

There is still a need for safe, efficient and low-cost coronavirus disease 2019 (COVID-19) vaccines that can stop transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we evaluated a vaccine candidate based on a live recombinant Newcastle disease virus (NDV) that expresses a stable version of the spike protein in infected cells as well as on the surface of the viral particle (AVX/COVID-12-HEXAPRO, also known as NDV-HXP-S). This vaccine candidate can be grown in embryonated eggs at low cost similar to influenza virus vaccines and it can also be administered intranasally, potentially to induce mucosal immunity. We evaluated this vaccine candidate in prime-boost regimens via intramuscular, intranasal, or intranasal followed by intramuscular routes in an open label non-randomized non-placebo-controlled phase I clinical trial in Mexico in 91 volunteers. The primary objective of the trial was to assess vaccine safety and the secondary objective was to determine the immunogenicity of the different vaccine regimens. In the interim analysis reported here, the vaccine was found to be safe and the higher doses tested were found to be immunogenic when given intramuscularly or intranasally followed by intramuscular administration, providing the basis for further clinical development of the vaccine candidate. The study is registered under ClinicalTrials.gov identifier NCT04871737. Funding was provided by Avimex and CONACYT.

Maturation Phenotype of Peripheral Blood Monocyte/Macrophage After Stimulation with Lipopolysaccharides in Irritable Bowel Syndrome

BACKGROUND/AIMS: Abnormal immune regulation and increased intestinal permeability augmenting the passage of bacterial molecules that can activate immune cells, such as monocytes/macrophages, have been reported in irritable bowel syndrome (IBS). The aim was to compare the maturation phenotype of monocytes/macrophages (CD14+) from IBS patients and controls in the presence or absence of Escherichia coli lipopolysaccharides (LPS), in vitro. METHODS: Mononuclear cells were isolated from peripheral blood of 20 Rome II-IBS patients and 19 controls and cultured with or without LPS for 72 hours. The maturation phenotype was examined by flow cytometry as follows: M1-Early (CD11c⁺CD206⁻), M2-Advanced (CD11⁻CD206⁺CX3CR1⁺); expression of membrane markers was reported as mean fluorescence intensity (MFI). The Mann-Whitney test was used and significance was set at P < 0.05. RESULTS: In CD14+ cells, CD11c expression decreased with vs without LPS both in IBS (MFI: 8766.0 ± 730.2 vs 12 920.0 ± 949.2, P < 0.001) and controls (8233.0 ± 613.9 vs 13 750.0 ± 743.3, P < 0.001). M1-Early cells without LPS, showed lower CD11c expression in IBS than controls (MFI: 11 540.0 ± 537.5 vs 13 860.0 ± 893.7, P = 0.040), while both groups showed less CD11c in response to LPS (P < 0.01). Furthermore, the percentage of “Intermediate” (CD11c⁺CD206⁺CX3CR1⁺) cells without LPS, was higher in IBS than controls (IBS = 9.5 ± 1.5% vs C = 4.9 ± 1.4%, P < 0.001). Finally, fractalkine receptor (CX3CR1) expression on M2-Advanced cells was increased when treated with LPS in controls but not in IBS (P < 0.001). CONCLUSIONS: The initial phase of monocyte/macrophage maturation appears to be more advanced in IBS compared to controls. However, the decreased CX3CR1 in patients with IBS, compared to controls, when stimulated with LPS suggests a state of immune activation in IBS.

Gastric cancer progression associated with local humoral immune responses.

BACKGROUND: Although the association between H. pylori and gastric cancer has been well described, the alterations studies are scarce in the humoral immune response in specific anatomical areas of stomach and during the stages of gastric cancer. The aim in this study was to determine the influence of humoral immune responses against H. pylori infection on gastric carcinoma. METHODS: We selected 16 gastric cancer cases and approximately one matched control per case at the National Institute of Medical Sciences and Nutrition Salvador Zubirán (INCMNSZ); all the cases met the inclusion criteria for the study. We obtained three biopsies from each patient and from each of the predetermined regions of the stomach: antrum, angular portion, corpus, and fundus. From the patients with gastric cancer, additional biopsy specimens were obtained from tumor mid-lesion and tumor margin, and additional specimens were collected at least 2 and 5 cm from the tumor margin. We compared IgA levels against H. pylori in each area of stomach between cases and controls as well as between early and advanced stages of gastric cancer. RESULTS: IgA values were strikingly elevated in cancer cases compared with control subjects; a value that was even higher in the distant periphery of tumor but was remarkably decreased toward the carcinoma lesion. The advanced stages of gastric cancer demonstrated the relapse of the humoral immune response in the mid-lesion region of the tumor compared with the tumor margins and adjacent non-tumor tissue. CONCLUSIONS: Gastric cancer is characterized by progressive accumulation of a concentrated, specific IgA response against H. pylori, beginning with an abnormal increase in the entire stomach but particularly in the adjacent non-tumor tissue. Thus, it is possible that this strong immune response also participates in some degree in the damage and in the development of gastric cancer to some extent.

A Survey Using the Social Networks Revealed Poor Knowledge on Fecal Microbiota Transplantation

No abstract available.