1954. Immunogenicity against SARS CoV-2 ancestral strain and variants of two new COVID-19 recombinant adjuvanted vaccines compared to BNT162b2 as a third dose following two doses of BNT162b2: a single-blinded multicenter randomized controlled trial

Background

New adjuvanted recombinant protein vaccines against coronavirus disease 2019 (COVID-19) as heterologous boosters could maximize the benefits of vaccination against SARS CoV-2.

Methods

In this randomized, single-blinded, multicenter trial, adults who had received two doses of Pfizer-BioNTech mRNA vaccine (BNT162b2) 3–7 months before were randomly assigned to receive a boost of BNT162b2, Sanofi/GSK SARS-CoV-2 adjuvanted recombinant protein MV D614 (monovalent parental formulation) or SARS-CoV-2 adjuvanted recombinant protein MV B.1.351 vaccine (monovalent Beta formulation). The primary endpoint was the percentage of subjects with a ≥ 10-fold increase in neutralizing antibody titers for the Wuhan (D614) and B.1.351 (Beta) SARS-CoV-2 viral strains between D0 and D15.

Results

The percentages of participants whose neutralizing antibody titers against the Wuhan (D614) SARS-CoV-2 strain increased by a factor ≥ 10 between Day 0 and Day 15 was 55.3% (95% CI 43.4-66.7) in MV(D614) group (n=76), 76.1% (64.5-85.4) in MV(Beta) group (n=71) and 63.2% (51.3-73.9) in BNT162b2 group (n=76). These percentages were 44.7% (33.3-56.6), 84.5% (74.0-92.0) and 51.3% (39.6-63.0) for the B.1.351 (Beta) viral strain, respectively. Higher neutralizing antibodies rates against Delta and Omicron BA.1 variants were also elicited after Sanofi/GSK MV(Beta) vaccine compared to the other vaccines. Comparable reactogenicity profile was observed the three vaccines. Table 1.Characteristics of patients at inclusion (per-protocol population).Figure 2.Neutralizing antibodies against D614 (wild-type; Wuhan) SARS-CoV-2 and variants Beta, Delta and Omicron BA.1 at D0, D15 and D28 after the boost dose (“post D3”)with Sanofi/GSK-D614, Sanofi/GSK-B.1.351 or BNT162b2 (per-protocol population); dotted line represents the positivity threshold.Figure 4.Rates and grades of severity of solicited adverse events reported from D0 to D7 by participants from the three randomized groups of the safety population (G1, Sanofi/GSK-D614; G2, Sanofi/GSK-B.1.351; G3, BNT162b2) according to the Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials (Modified FDA scale/September 2007)

Conclusion

All three vaccines boosted antibodies and neutralizing response after BNT162b2 initial course. Heterologous boosting with the Sanofi/GSK SARS-CoV-2 adjuvanted recombinant protein vaccine B.1.351 (Beta formulation) provided higher neutralizing antibodies response rates against variants, including Omicron BA.1, compared with the mRNA BNT162b2 vaccine.

Disclosures

Odile Launay, MD, PhD, AstraZeneca: Financial|GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support|Johnson & Johnson: Advisor/Consultant|Johnson & Johnson: Grant/Research Support|MD: Advisor/Consultant|Moderna: Advisor/Consultant|MSD: Data safety monitoring board|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant|Sanofi Pasteur: Grant/Research Support|Sanofi Pasteur: Data safety monitoring board Liem Binh Luong, MD, Pfizer: Advisor/Consultant|Pfizer: Honoraria Karine Lacombe, MD, PhD, Gilead: Advisor/Consultant|Janssen: Grant/Research Support|MSD: Grant/Research Support|ViiV Healthcare: Grant/Research Support Elisabeth Botelho-Nevers, MD, PHD, Janssen: Board Member|Pfizer: Board Member|Sanofi Pasteur: Board Member.

Fatty acid composition of phospholipids and triacylglycerols in the flesh of the thick-lipped grey mullet (Chelon labrosus) living in Tunisian geothermal water and seawater: A comparative study

This study was conducted to elucidate the effects of rearing conditions on the composition of different phospholipid (PLs) classes and triacylglycerols (TAG) of the thick-lipped grey mullet (Chelon labrosus), a muscle originating from seawater and geothermal water. The major fatty acids in the examined lipid classes of the two fish groups were palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n-9), linoleic acid (C18:2n-6), arachidonic acid (C20:4n-6), eicosapentaenoic acid (C20:5n-3), and docosahexaenoic acid (C22:6n-3). The analyses demonstrated that the fatty acid profiles of the PL classes in the seawater fish group were characterized by the predominance of n-3 polyunsaturated fatty acids (PUFA). By contrast, in geothermal fish, the distribution of PUFA series proportions differed between the phospholipid fractions. It was found PUFA n-3 was particularly abundant in PS and PI, while the n-6 series dominated the PC and PE PUFA group. Nonetheless, it was found that neutral lipid fatty acids were characterized by saturated fatty acids (SFA) followed by monounsaturated fatty acids (MUFA) in the seawater fish and by PUFA in the geothermal fish. The results presented here give useful information on the role of lipid classes in the physiological adaptation of C. labrosus which can serve for the optiminzation of these aquaculture systems.

NLRP3 is involved in long bone edification and the maturation of osteogenic cells

Overexpression of the nucleotide-binding leucine-rich repeat protein 3 (NLRP3) inflammasome in chronic auto-immune diseases leads to skeletal anomalies, with severe osteopenia due to the activation of osteoclasts. Reproducing this phenotype in Nlrp3 knock-in mice has provided insights into the role of NLRP3 in bone metabolism. We studied the role of NLRP3 in physiological bone development using a complete Nlrp3 knock-out mouse model. We found impaired skeletal development in Nlrp3-/- mice, resulting in a shorter stature than that of Nlrp3+/+  mice. These growth defects were associated with altered femur bone growth, characterized by a deficient growth plate and an osteopenic profile of the trabeculae. No differences in osteoclast recruitment or activity were observed. Instead, Nlrp3-/- femurs showed a less mineralized matrix in the trabeculae than those of Nlrp3+/+  mice, as well as less bone sialoprotein (BSP) expressing hypertrophic chondrocytes. In vitro, primary osteoblasts lacking NLRP3 expression showed defective mineralization, together with the downregulation of BSP expression. Finally, follow-up by micro-CT highlighted the role of NLPR3 in bone growth, occurring early in living mice, as the osteopenic phenotype diminishes over time. Overall, our data suggest that NLRP3 is involved in bone edification via the regulation of hypertrophic chondrocyte maturation and osteoblast activity. Furthermore, the defect appeared to be transitory, as the skeleton recovered with aging.

Interleukin-22 regulates interferon lambda expression in a mice model of pseudomonas aeruginosa pneumonia

BACKGROUND

Interleukin (IL)-22 is a cytokine involved in tissue protection and repair following lung pathologies. Interferon (IFN)-λ cytokines displayed similar properties during viral infection and a synergy of action between these two players has been documented in the intestine. We hypothesize that during Pseudomonas aeruginosa challenge, IL-22 up-regulates IFN-λ and that IFN-λ exhibits protective functions during Pseudomonas aeruginosa acute pneumonia model in mice.

METHODS

Using an in vitro human alveolar epithelial cell line A549, we assessed the ability of IL-22 to enhance IFN-λ expression during infection. IFN-λ protective function was evaluated in an acute mouse pneumonia model.

RESULTS

We first demonstrated in murine lungs that only type-II alveolar cells express IL-22 receptor and that IL-22 treatment of A549 cell line up-regulates IFN-λ expression. In a murine acute pneumonia model, IL-22 administration maintained significant IFN-λ levels in the broncho-alveolar fluids whereas IL-22 neutralization abolished IFN-λ up-regulation. In vivo administration of IFN-λ during Pseudomonas aeruginosa pneumonia improves mice outcome by dampening neutrophil recruitment and decreasing epithelium damages.

DISCUSSION

We show here that IL-22 regulates IFN-λ levels during Pseudomonas aeruginosa pneumonia.

Interleukin-22 level is negatively correlated with neutrophil recruitment in the lungs in a Pseudomonas aeruginosa pneumonia model

Pseudomonas aeruginosa is a major threat for immune-compromised patients. Bacterial pneumonia can induce uncontrolled and massive neutrophil recruitment ultimately leading to acute respiratory distress syndrome and epithelium damage. Interleukin-22 plays a central role in the protection of the epithelium. In this study, we aimed to evaluate the role of interleukin-22 and its soluble receptor IL-22BP in an acute Pseudomonas aeruginosa pneumonia model in mice. In this model, we noted a transient increase of IL-22 during Pseudomonas aeruginosa challenge. Using an antibody-based approach, we demonstrated that IL-22 neutralisation led to increased susceptibility to infection and to lung damage correlated with an increase in neutrophil accumulation in the lungs. On the contrary, rIL-22 administration or IL-22BP neutralisation led to a decrease in mouse susceptibility and lung damage associated with a decrease in neutrophil accumulation. This study demonstrated that the IL-22/IL-22BP system plays a major role during Pseudomonas aeruginosa pneumonia by moderating neutrophil accumulation in the lungs that ultimately leads to epithelium protection.

Hyperinvasive Meningococci Induce Intra-nuclear Cleavage of the NF-κB Protein p65/RelA by Meningococcal IgA Protease

Differential modulation of NF-κB during meningococcal infection is critical in innate immune response to meningococcal disease. Non-invasive isolates of Neisseria meningitidis provoke a sustained NF-κB activation in epithelial cells. However, the hyperinvasive isolates of the ST-11 clonal complex (ST-11) only induce an early NF-κB activation followed by a sustained activation of JNK and apoptosis. We show that this temporal activation of NF-κB was caused by specific cleavage at the C-terminal region of NF-κB p65/RelA component within the nucleus of infected cells. This cleavage was mediated by the secreted 150 kDa meningococcal ST-11 IgA protease carrying nuclear localisation signals (NLS) in its α-peptide moiety that allowed efficient intra-nuclear transport. In a collection of non-ST-11 healthy carriage isolates lacking NLS in the α-peptide, secreted IgA protease was devoid of intra-nuclear transport. This part of iga polymorphism allows non-invasive isolates lacking NLS, unlike hyperinvasive ST-11 isolates of N. meningitides habouring NLS in their α-peptide, to be carried asymptomatically in the human nasopharynx through selective eradication of their ability to induce apoptosis in infected epithelial cells.

Strains of Neisseria meningitidis isolated from patients induce apoptotic cell death, whereas strains isolated from healthy carriage isolates do not. Part of the difference has been shown to arise from differential modulation of NF-κB during meningococcal infection. While non-invasive isolates of Neisseria meningitidis provoke a sustained NF-κB activation in epithelial cells, hyperinvasive isolates only induce an early NF-κB activation followed by a sustained activation of JNK and apoptosis. Here, we elucidate the mechanism conferring this differential modulation, specifically showing that ST-11 hyperinvasive isolates promote specific cleavage of NF-κB p65/RelA component in a manner dependent on the secreted IgA protease. This cleavage occurs within the nuclear compartment. Secreted IgA protease from non-invasive isolates was unable to reach the nuclear compartment of infected cells, resulting in a sustained activation of NF-κB activity and subsequent cytoprotective effect. Modulation of NF-κB-related signaling is likely a double-edged sword to decide the fate of meningococcal infection.

Virulence and enterobacterial repetitive intergenic consensus PCR of Vibrio alginolyticus strains isolated from Tunisian cultured gilthead sea bream and sea bass outbreaks

Vibrio alginolyticus was isolated from the internal organs of diseased gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) cultured in two fish farms located on the Tunisian Mediterranean coast, from 2003 to 2005. After phenotypic characterisation, a selection of 34 isolates from gilthead sea bream and sea bass were molecularly typed by repetitive intergenic consensus PCR (ERIC-PCR) showing a high polymorphism among the isolated strains (19 genotypes). Most of the isolates were resistant to atleast two antimicrobial agents. All the tested strains were resistant to ampicillin. However, 91.17% were resistant to nitrofurantoin and 35.29% to tetracycline. Several strains isolated from diseased gilthead sea bream and sea bass were tested for virulence in both fish species by intraperitoneal injection. The selected isolates (n=7) were pathogenic for gilthead sea bream and sea bass. LD(50) values ranged from 5.01 x 10(4) to 6.20 x 10(7)CFU/fish. This is the first report on characterisation and virulence of V. alginolyticus for sea bass and sea bream in Tunisia.

[Infantile visceral leishmaniasis: difficult diagnosis in cases complicated by hemophagocytosis]

BACKGROUND

Hemophagocytosis has already been reported in cases of visceral leishmaniasis and thus may complicate search for diagnosis.

CASE REPORT

A previously healthy 2 year-old boy was referred for fever and splenomegaly with pancytopenia. An initial diagnosis of kala-azar was refuted because of absence of biological inflammatory syndrome, negativity of bone-marrow aspiration and splenic ponction and of specific serology. After three months of clinical deterioration and apparition of active hemophagocytosis, both bone marrow aspiration and specific serology for visceral leishmaniasis became positive. The boy was given sodium stibogluconate for 20 days; he improved gradually with complete and definitive remission.

CONCLUSION

Diagnosis of visceral leishmaniasis may be difficult, even in countries where this condition is relatively frequent; the association with hemophagocytosis is possible and does not constitute a poor factor of prognosis if specific therapy is proposed.

[Infantile cystinosis. A new Tunisian case]

A case of cystinosis in a three and a half-year-old is reported. Suggestive manifestations included severe rickets, small stature, and complex renal tubule dysfunction meeting the criteria for secondary Fanconi syndrome. Diagnosis was established by the discovery of retinal lesions upon ophtalmologic evaluation and, above all, by the finding that intracellular leukocyte cystine levels were increased to 16 mumol of 1/2 cystine per gram protein. Cystinosis is severe because it inevitably leads to renal failure. Much hope is currently placed in the use of cysteamine to delay this and other complications. At present, early antenatal diagnosis during the first ten weeks of pregnancy is needed in high-risk families to allow elective termination of pregnancy within the legal time limit.