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(1) Background: This study aimed to compare the immunogenicity of the mix-and-match CoronaVac/BNT162b2 vaccination to the homologous CoronaVac/CoronaVac regimen. (2) Methods: We conducted a simple-blinded randomized superiority trial to measure SARS-CoV-2 neutralization antibodies and anti-spike receptor binding domain (RBD) IgG concentrations in blood samples of participants who had received the first dose of CoronaVac vaccine followed by a dose of BNT162b2 or CoronaVac vaccine. The primary endpoint for immunogenicity was the serum-neutralizing antibody level with a percentage of inhibition at 90% at 21–35 days after the boost. A difference of 25% between groups was considered clinically relevant. (3) Results: Among the 240 eligible participants, the primary endpoint data were available for 100 participants randomly allocated to the mix-and-match group versus 99 participants randomly allocated to the homologous dose group. The mix-and-match regimen elicited significantly higher levels of neutralizing antibodies (median level of 96%, interquartile range (IQR) (95–97) versus median level of 94%, IQR (81–96) and anti-spike IgG antibodies (median level of 13,460, IQR (2557–29,930) versus median level of 1190, IQR (347–4964) compared to the homologous group. Accordingly, the percentage of subjects with a percentage of neutralizing antibodies > 90% was significantly higher in the mix-and-match group (90.0%) versus the homologous (60.6%). Interestingly, no severe events were reported within 30 days after the second dose of vaccination in both groups. (4) Conclusions: Our data showed the superiority of the mix-and-match CoronaVac/BNT162b2 vaccination compared to the CoronaVac/CoronaVac regimen in terms of immunogenicity, thus constituting a proof-of-concept study supporting the use of inactivated vaccines in a mix-and-match strategy while ensuring good immunogenicity and safety. [ABSTRACT FROM AUTHOR]

This study shows, for the first time, natural Leishmania infection among Jaculus spp. in an endemic region of Tataouine, South Tunisia. To better characterize the transmission cycles in this complex focus of mixed transmission, Leishmania detection and species identification were performed by direct examination, internal transcribed spacer-1 (ITS1)-PCR-restriction fragment length polymorphism (RFLP), and sequencing of Jaculus (J.) jaculus (Linnaeus, 1758) and J. hirtipes (Lichtenstein, 1823) rodent species, which are frequently encountered in this area. Leishmania parasites were observed in 19 (41.3%) smears, while DNA parasites were detected in 28 (60.9%) Jaculus spp. spleens; among them, 12 (54.5%) were from 22 J. jaculus individuals and 16 (66.7%) were from 24 J. hirtipes individuals. Leishmania parasites were confirmed as Leishmania (L.) killicki (syn. L. tropica) in two J. hirtipes individuals (4.3%) and L. major (n = 24; 52.2%) in 10 J. jaculus and 14 J. hirtipes individuals. This finding represents the first evidence of natural infection with Leishmania parasites in rodents belonging to the Jaculus genus, providing the rationale to consider them as potential reservoir hosts of Old World Leishmania parasites in Tunisia and North Africa. [ABSTRACT FROM AUTHOR]

Seroprevalence studies are essential to get an accurate estimate of the actual SARS-CoV-2 diffusion within populations. We report on the findings of the first serosurvey conducted in Tunis prior to the implementation of mass vaccination and analyzed factors associated with seropositivity. A household cross sectional survey was conducted (March–April 2021) in Tunis, spanning the end of the second wave and the beginning of the third wave of COVID-19. SARS-CoV-2 specific immunoglobulin G (IgG) antibodies to the spike (S-RBD) or the nucleocapsid (N) proteins were detected by in-house ELISA tests. The survey included 1676 individuals from 431 households. The mean age and sex ratio were 43.3 ± 20.9 years and 0.6, respectively. The weighted seroprevalence of anti-N and/or anti-S-RBD IgG antibodies was equal to 38.0% (34.6–41.5). In multivariate analysis, age under 10, no tobacco use, previous diagnosis of COVID-19, a history of COVID-19 related symptoms and contact with a COVID-19 case within the household, were independently associated with higher SARS-CoV-2 seroprevalence. More than one third of people living in Tunis obtained antibodies to SARS-CoV-2. Further studies are needed to monitor changes in these figures as Tunisian population is confronted to the subsequent epidemic waves and to guide the vaccine strategy. [ABSTRACT FROM AUTHOR]

Simple Summary: Rodents systematically represent a major issue owing to their biodiversity assessment. These micromammals exhibit phenotypic and genetic diversity and can be found in different ecosystems. The current study was undertaken to examine the morphometric and genetic patterns recently adapted by Jaculus (J.) jaculus in Tunisia. Moreover, we investigated micro-geographic clustering according to the species and/or the biotope ecosystem. Forty-six rodents were captured and analyzed for body measurements. At the genetic level, we confirmed the presence of two species, J. jaculus and J. hirtipes, but we found that each of these rodent species harbored two phylogroups that were genetically distant without any geographical and/or environmental structuring. The taxonomy of the Lesser Egyptian jerboa, Jaculus (J.) jaculus (Dipodinae subfamily), was recently reevaluated, and the taxonomic status was defined by the presence of two cryptic species, J. jaculus (Linnaeus 1758) and J. hirtipes (Lichtenstein, 1823), with a higher genetic divergence in the sympatric North African populations than in other studied parapatric populations. Using phylogenetic analysis of the cytochrome b (Cytb) gene from 46 specimens, we confirmed the new status in Tunisia; rodents were collected from two different biotopes belonging to the same locality at the ecological level (mountainous vs. Saharan) in the south of the country. The study of the eye lens weight of these specimens allowed the definition of a cutoff value (58.5 g), categorizing juveniles from adults. Moreover, this study confirmed the phylotaxonomic status of J. jaculus in Tunisia, as recently illustrated, into two distinct species, J. jaculus and J. hirtipes, and recorded for the first time the presence of two phylogroups among each of these rodent species. The lack of clear micro-geographical structure and biotope specificity between the two rodent species and their phylogroups was also highlighted. [ABSTRACT FROM AUTHOR]

Background: Many sand fly species are implicated in the transmission cycle of Leishmania parasites around the world. Incriminating new sand flies species, as vectors of Leishmania is crucial to understanding the parasite--vector transmission cycle in different areas in Tunisia and surrounding countries. Findings: Seventy-four unfed females belonging to the genera Sergentomyia and Phlebotomus were collected in South Tunisia between June and November 2014, using sticky papers. PCR-RFLP (Restriction Fragment Length Polymorphism) analysis of the internal transcribed spacer 1 (ITS1) was used for Leishmania parasites detection and identification. Leishmania (L.) major (Yakimoff & Shokkor, 1914) was identified within two Sergentomyia (S.) minuta (Rondani, 1843) and one Phlebotomus papatasi (Scopoli, 1786). Conclusion: This is the first report of L. major identified from S. minuta in Tunisia. This novel finding enhances the understanding of the transmission cycle of L. major parasites of cutaneous leishmaniasis in an endemic area in South Tunisia. [ABSTRACT FROM AUTHOR]

Incriminating new rodent species, as reservoir hosts of Leishmania parasites is crucial for understanding the transmission cycle of cutaneous leishmaniasis in Tunisia. Ctenodactylus ( C .) gundi was previously described as extremely abundant in all Tunisian Leishmania ( L .) tropica foci in south Tunisia besides its presence in L . major endemic area. The aim of this study was to detect Leishmania species parasites among C . gundi in two endemic regions in Tunisia: Sidi Bouzid and Tataouine. Total DNA was isolated from the spleens and the livers of 92 C . gundi . Leishmaniasis clinical manifestations were detected among 11 rodents (12%). Leishmania parasites were detected in 30 (32.6%) rodents using direct exam method. Leishmania DNA was detected in 40 (43.5%) C . gundi by combining results among spleens and livers using ITS1-PCR. Positive samples were confirmed to be L . major except for only one specimen which was L. tropica . These results demonstrated, for the first time, the high natural infection rate of C . gundi with L . major parasites in Tunisia. Hence, C . gundi should be considered as potential reservoir host of Leishmania parasites causing cutaneous leishmaniasis in Tunisia. [ABSTRACT FROM AUTHOR]

The taxonomy of the Lesser Egyptian jerboa, Jaculus ( J .) jaculus (Dipodinae subfamily), was recently reevaluated, and the taxonomic status was defined by the presence of two cryptic species, J . jaculus (Linnaeus 1758) and J . hirtipes (Lichtenstein, 1823), with a higher genetic divergence in the sympatric North African populations than in other studied parapatric populations. Using phylogenetic analysis of the cytochrome b ( Cytb ) gene from 46 specimens, we confirmed the new status in Tunisia; rodents were collected from two different biotopes belonging to the same locality at the ecological level (mountainous vs. Saharan) in the south of the country. The study of the eye lens weight of these specimens allowed the definition of a cutoff value (58.5 g), categorizing juveniles from adults. Moreover, this study confirmed the phylotaxonomic status of J . jaculus in Tunisia, as recently illustrated, into two distinct species, J . jaculus and J . hirtipes , and recorded for the first time the presence of two phylogroups among each of these rodent species. The lack of clear micro-geographical structure and biotope specificity between the two rodent species and their phylogroups was also highlighted.