On March 13, 2021, Tunisia started a widespread immunization program against SARS-CoV-2 utilizing different vaccinations that had been given emergency approval. Herein, we followed prospectively a cohort of participant who received COVID-19 vaccine (Pfizer BioNTech and Sputnik-Gameleya V). The goal of this follow-up was to define the humoral and cellular immunological profile after immunization by assessing neutralizing antibodies and IFN- γ release. 26 vaccinated health care workers by Pfizer BioNTech (n=12) and Sputnik-Gameleya V (n=14) were enrolled from June to December 2021 in Military hospital of Tunis. All consenting participants were sampled for peripheral blood after three weeks of vaccination. The humoral response was investigated by the titer of anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies to S1 protein. The CD4 and CD8 T cell responses were evaluated by the QuantiFERON® SARS-CoV-2 (Qiagen® Basel, Switzerland). Regardless the type of vaccine, the assessment of humoral and cellular response following vaccination showed a strong involvement of the later with expression of IFN-γ as compared to antibodies secretion. Moreover, we showed that people with past SARS-CoV-2 infection developed high levels of antibodies than those who are not previously infected. However, no significant difference was detected concerning interferon gamma (IFN-γ) expression by CD4 and CD8 T cells in health care worker (HCW) previously infection or not with COVID-19 infection. Analysis of immune response according to the type of vaccine, we found that Pfizer BioNTech induced high level of humoral response (91.66%) followed by Sputnik-Gameleya V (64.28%). However, adenovirus vaccine gave a better cellular response (57.14%) than mRNA vaccine (41.66%). Regarding the immune response following vaccine doses, we revealed a significant increase of neutralizing antibodies and IFN-γ release by T cells in patients fully vaccinated as compared to those who have received just one vaccine. Collectively, our data revealed a similar immune response between Pfizer BioNTech and Sputnik-Gameleya V vaccine with a slight increase of humoral response by mRNA vaccine and cellular response by adenovirus vaccine. It's evident that past SARS-CoV-2 infection was a factor that contributed to the vaccination's increased immunogenicity. However, the administration of full doses of vaccines (Pfizer BioNTech or Sputnik-Gameleya V) induces better humoral and cellular responses detectable even more than three months following vaccination.

As elevated levels of the soluble CXCL16 (sCXCL16) chemokine have been reported in severe coronavirus disease 2019 (COVID-19) patients, this study examined whether sCXCL16 concentration on the first day of hospitalization predicted death in COVID-19 patients. A total of 76 patients with COVID-19 were admitted to the Military Hospital of Tunis, Tunisia, between October 2020 and April 2021, and later classified as survivors or nonsurvivors based on their outcomes. At admission, the groups were matched by age, gender, comorbidities, and the percentage of patients with moderate conditions. On the first day of admission, serum's sCXCL16 concentrations were measured using a magnetic-bead assay. There was an eightfold increase in serum sCXCL16 levels in the nonsurvivors' group (3661.51 +/- 2464.87 pg/mL vs. 454.3 +/- 338.07 pg/mL, p < 0.0001). For the optimal cutoff value of sCXCL16 at 2095 pg/mL, we found a 94.6% sensitivity and a 97.4% specificity, with an area under curve of 0.981 (p = 5.03E-08; 95% confidence interval [95% CI]: 0.951-1.0114). Considering the risk of death at a concentration above the threshold, the unadjusted odds ratio was 36 (p < 0.0001). The adjusted odd ratio was estimated at 1.003 (p < 0.0001; 95% CI: 1.002-1.004). Finally, there was a significant difference between survival and nonsurvival groups in leukocyte numbers (p = 0.006), lymphocytes (p = 0.001), polymorphonuclear neutrophils (p = 0.001), and C-reactive protein levels (p = 0.007), except for monocytes (p = 0.881). Based on these results, sCXCL16 level could be used for detecting nonsurvival COVID-19 patients. Therefore, we recommend assessing this marker in hospitalized COVID-19 patients.

Prunus L. (Rosaceae), a genus of over 230 species, exhibits gametophytic self-incompatibility system (GSI). In this study, we explored the patterns of variability in Plum genotypes carrying different reproductive systems, using 36 microsatellite markers (SSRs) and the S-locus. The analysis of genetic diversity showed a rich genetic variability of the studied genotypes. Linkage Disequilibrium decayed rapidly in analyzed plums reaching the significant value (r(2) = 0.1) at 7.5 cM. Also, we examined the patterns of variability at the end of the sixth linkage group to emphasize the effect of the S-locus on the surrounding region. The genetic diversity in the genomic neighborhood of the S-locus is related to the negative frequency dependent selection (NFDS) which can extend the high polymorphism at the selected locus to closely linked neutral sites. We conducted a drought stress on Tunisian plum to test their response. The analysis of five morphological parameters tested under drought conditions allowed selecting five plum genotypes (one hexploid and four diploid) characterized by their important tolerance to drought stress. These genotypes may be selected as important rootstock for varietal improvement.

Purpose: The aim of our study was to evaluate the prevalence of aPLAs among Tunisian critically-ill covid19 and non-covid19 patients and to investigate the clinical significance of aPLAs by determining the SOFA score and their respiratory failure during their ICU stay. Methods: We conducted a prospective observational cohort study including critically ill COVID-19 patients and non-COVID-19 patients with pulmonary origin sepsis, admitted to the intensive care unit. Blood samples were collected on days 1, 3, 5, 8 and 10 of hospitalization in order to measure titers of anti-cardiolipin (aCL), anti-phosphatidylserine (aPS) by chemiluminescence immunoassay. Results: We enrolled 43 COVID-19 patients and 31 non COVID-19 with pulmonary origin sepsis. In-hospital mortality rate was significantly higher (p=0.026) in COVID-19 patients (79%). 58.8% of COVID-19 patients were aPLA positive; however, only 22.5% of the non-COVID-19 were positive for aPLA (p=0.002). A significant positive correlation existed between respiratory SOFA component at days 3, 5, 8 and 10 and anti-phospholipid antibodies concentrations. Conclusion: Based on our results, for the first time, anti-phospholipid antibodies may be used as an independent indicator of respiratory organ failure in critically ill patients, to stratify and assess the prognosis of pulmonary origin sepsis and COVID-19.