A single-dose live-attenuated YF17D-vectored SARS-CoV-2 vaccine candidate.

The expanding pandemic of coronavirus disease 2019 (COVID-19) requires the development of safe, efficacious and fast-acting vaccines. Several vaccine platforms are being leveraged for a rapid emergency response1. Here we describe the development of a candidate vaccine (YF-S0) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that uses live-attenuated yellow fever 17D (YF17D) vaccine as a vector to express a noncleavable prefusion form of the SARS-CoV-2 spike antigen. We assess vaccine safety, immunogenicity and efficacy in several animal models. YF-S0 has an excellent safety profile and induces high levels of SARS-CoV-2 neutralizing antibodies in hamsters (Mesocricetus auratus), mice (Mus musculus) and cynomolgus macaques (Macaca fascicularis), and-concomitantly-protective immunity against yellow fever virus. Humoral immunity is complemented by a cellular immune response with favourable T helper 1 polarization, as profiled in mice. In a hamster model2 and in macaques, YF-S0 prevents infection with SARS-CoV-2. Moreover, a single dose conferred protection from lung disease in most of the vaccinated hamsters within as little as 10 days. Taken together, the quality of the immune responses triggered and the rapid kinetics by which protective immunity can be attained after a single dose warrant further development of this potent SARS-CoV-2 vaccine candidate.

Iron regulates the quiescence of naive CD4 T cells by controlling mitochondria and cellular metabolism.

In response to an immune challenge, naive T cells undergo a transition from a quiescent to an activated state acquiring the effector function. Concurrently, these T cells reprogram cellular metabolism, which is regulated by iron. We and others have shown that iron homeostasis controls proliferation and mitochondrial function, but the underlying mechanisms are poorly understood. Given that iron derived from heme makes up a large portion of the cellular iron pool, we investigated iron homeostasis in T cells using mice with a T cell-specific deletion of the heme exporter, FLVCR1 [referred to as knockout (KO)]. Our finding revealed that maintaining heme and iron homeostasis is essential to keep naive T cells in a quiescent state. KO naive CD4 T cells exhibited an iron-overloaded phenotype, with increased spontaneous proliferation and hyperactive mitochondria. This was evidenced by reduced IL-7R and IL-15R levels but increased CD5 and Nur77 expression. Upon activation, however, KO CD4 T cells have defects in proliferation, IL-2 production, and mitochondrial functions. Iron-overloaded CD4 T cells failed to induce mitochondrial iron and exhibited more fragmented mitochondria after activation, making them susceptible to ferroptosis. Iron overload also led to inefficient glycolysis and glutaminolysis but heightened activity in the hexosamine biosynthetic pathway. Overall, these findings highlight the essential role of iron in controlling mitochondrial function and cellular metabolism in naive CD4 T cells, critical for maintaining their quiescent state.

Microbiome Dysbiosis, Dietary Intake and Lifestyle-Associated Factors Involve in Epigenetic Modulations in Colorectal Cancer: A Narrative Review.

Background: Colorectal cancer is the second cause of cancer mortality and the third most commonly diagnosed cancer worldwide. Current data available implicate epigenetic modulations in colorectal cancer development. The health of the large bowel is impacted by gut microbiome dysbiosis, which may lead to colon and rectum cancers. The release of microbial metabolites and toxins by these microbiotas has been shown to activate epigenetic processes leading to colorectal cancer development. Increased consumption of a 'Westernized diet' and certain lifestyle factors such as excessive consumption of alcohol have been associated with colorectal cancer.Purpose: In this review, we seek to examine current knowledge on the involvement of gut microbiota, dietary factors, and alcohol consumption in colorectal cancer development through epigenetic modulations.Methods: A review of several published articles focusing on the mechanism of how changes in the gut microbiome, diet, and excessive alcohol consumption contribute to colorectal cancer development and the potential of using these factors as biomarkers for colorectal cancer diagnosis.Conclusions: This review presents scientific findings that provide a hopeful future for manipulating gut microbiome, diet, and alcohol consumption in colorectal cancer patients' management and care.

Akt Plays Differential Roles during the Life Cycles of Acute and Persistent Murine Norovirus Strains in Macrophages.

Akt (protein kinase B) is a key signaling protein in eukaryotic cells that controls many cellular processes, such as glucose metabolism and cell proliferation, for survival. As obligate intracellular pathogens, viruses modulate host cellular processes, including Akt signaling, for optimal replication. The mechanisms by which viruses modulate Akt and the resulting effects on the infectious cycle differ widely depending on the virus. In this study, we explored the effect of Akt serine 473 phosphorylation (p-Akt) during murine norovirus (MNV) infection. p-Akt increased during infection of murine macrophages with acute MNV-1 and persistent CR3 and CR6 strains. Inhibition of Akt with MK2206, an inhibitor of all three isoforms of Akt (Akt1/2/3), reduced infectious virus progeny of all three virus strains. This reduction was due to decreased viral genome replication (CR3), defective virus assembly (MNV-1), or altered cellular egress (CR3 and CR6) in a virus strain-dependent manner. Collectively, our data demonstrate that Akt activation increases in macrophages during the later stages of the MNV infectious cycle, which may enhance viral infection in unique ways for different virus strains. The data, for the first time, indicate a role for Akt signaling in viral assembly and highlight additional phenotypic differences between closely related MNV strains. IMPORTANCE Human noroviruses (HNoV) are a leading cause of viral gastroenteritis, resulting in high annual economic burden and morbidity, yet there are no small-animal models supporting productive HNoV infection or robust culture systems producing cell culture-derived virus stocks. As a result, research on drug discovery and vaccine development against norovirus infection has been challenging, and no targeted antivirals or vaccines against HNoV are approved. On the other hand, murine norovirus (MNV) replicates to high titers in cell culture and is a convenient and widespread model in norovirus research. Our data demonstrate the importance of Akt signaling during the late stage of the MNV life cycle. Notably, the effect of Akt signaling on genome replication, virus assembly, and cellular egress is virus strain specific, highlighting the diversity of biological phenotypes despite small genetic variability among norovirus strains. This study is the first to demonstrate a role for Akt in viral assembly.

Circulation of multiple hepatitis B virus genotypes in individual pregnant women seeking antenatal care in northern Ghana.

BACKGROUND: Identification and monitoring of HBV genotype variations is important, since that can help forecast the likelihood of developing serious liver disease and how well patients respond to antiviral medication. Given that HBV genotyping tests are not widely available in our healthcare system, this study characterized HBV genotypes in pregnant women seeking prenatal treatment in northern Ghana. METHOD: By a cross-sectional approach, 2071 pregnant women seeking antenatal care in health facilities in northern Ghana were screened for HBV infection using hepatitis B surface antigen (HBsAg) rapid diagnostic test kit. The women were aged between 17 and 41 years, were of varying gravidae (primigravidae and multigravidae) and gestational age (first, second and third trimesters). A confirmatory PCR assay was used to detect HBsAg, and the distribution of HBV genotypes was determined using a nested PCR assay. RESULTS: Three HBV genotypes (A, D and E) were detected among the pregnant women, of which 175 (91.6%) had genotype E, 9 (4.7%) had mixed genotypes A and E, 5 (2.6%) had mixed genotypes D and E, and 2 (1.1) had mixed genotypes A, D and E. The proportions of women with the different HBV genotypes were independent of age (p = 0.925), gravidity (p = 0.193, χ2 = 4.729) and gestational age (p = 0.227, χ2 = 8.152). CONCLUSION: This study for the first-time characterized circulating HBV genotypes in pregnant women in northern Ghana, which reveals genotypes A and D are found in mixed infections with genotype E. The findings have clinical implications on the management of chronic HBV infection among pregnant women in northern Ghana.

Thyroid hormone profile in preeclampsia patients: a case control study.

Objective: Preeclamptic women are reported to have a higher incidence of thyroid dysfunction that correlates with the severity of preeclampsia. The aim of this study was to assess thyroid hormone profiles in in pregnant women with preeclampsia and gestational hypertension and the risk for thyroid dysfunction.Methods: In this study, age-matched pregnant females in the second trimester of pregnancy, diagnosed with preeclampsia (PE), gestational hypertension (GH), as cases, and apparently healthy normotensive (NT) pregnant woman as controls were recruited. Blood samples were drawn for the assessment of thyroid hormone (TSH, FT3 and FT4) levels and thyroid dysfunction.Results: Out of the total of 133 pregnant women recruited for this study, sub-clinical hypothyroidism was the only thyroid dysfunction common to all study groups, with a prevalence of 3.3% in both PE and NT groups, and 4.3% in the GH group. 1% of women in the PE group had sub-clinical hyperthyroidism, compared to 3.3% in the NT group. Although TSH and FT3 were elevated in normotensives, mean differences between the three groups were not statistically significant. However, mean FT4 levels in the GH group (12.99 ± 1.24) and PE group (12.33 ± 2.26), when compared to the control group (11.55 ± 1.94), were significantly higher (p < 0.05).Conclusion: Undiagnosed subclinical hypothyroidism was found in all the categories of pregnant women studied, which if uncontrolled, could increase the risk of pregnancy-related complications, especially in pregnant women with preeclampsia and gestational hypertension.

Altered Faecal Microbiota Composition and Structure of Ghanaian Children with Acute Gastroenteritis.

Acute gastroenteritis (AGE) is a disease of global public health importance. Recent studies show that children with AGE have an altered gut microbiota relative to non-AGE controls. Yet, how the gut microbiota differs in Ghanaian children with and without AGE remains unclear. Here, we explore the 16S rRNA gene-based faecal microbiota profiles of Ghanaian children five years of age and younger, comprising 57 AGE cases and 50 healthy controls. We found that AGE cases were associated with lower microbial diversity and altered microbial sequence profiles relative to the controls. The faecal microbiota of AGE cases was enriched for disease-associated bacterial genera, including Enterococcus, Streptococcus, and Staphylococcus. In contrast, the faecal microbiota of controls was enriched for potentially beneficial genera, including Faecalibacterium, Prevotella, Ruminococcus, and Bacteroides. Lastly, distinct microbial correlation network characteristics were observed between AGE cases and controls, thereby supporting broad differences in faecal microbiota structure. Altogether, we show that the faecal microbiota of Ghanaian children with AGE differ from controls and are enriched for bacterial genera increasingly associated with diseases.

Structure-Based Identification of Natural-Product-Derived Compounds with Potential to Inhibit HIV-1 Entry.

Broadly neutralizing antibodies (bNAbs) are potent in neutralizing a wide range of HIV strains. VRC01 is a CD4-binding-site (CD4-bs) class of bNAbs that binds to the conserved CD4-binding region of HIV-1 envelope (env) protein. Natural products that mimic VRC01 bNAbs by interacting with the conserved CD4-binding regions may serve as a new generation of HIV-1 entry inhibitors by being broadly reactive and potently neutralizing. This study aimed to identify compounds that mimic VRC01 by interacting with the CD4-bs of HIV-1 gp120 and thereby inhibiting viral entry into target cells. Libraries of purchasable natural products were virtually screened against clade A/E recombinant 93TH057 (PDB: 3NGB) and clade B (PDB ID: 3J70) HIV-1 env protein. Protein-ligand interaction profiling from molecular docking and dynamics simulations showed that the compounds had intermolecular hydrogen and hydrophobic interactions with conserved amino acid residues on the CD4-binding site of recombinant clade A/E and clade B HIV-1 gp120. Four potential lead compounds, NP-005114, NP-008297, NP-007422, and NP-007382, were used for cell-based antiviral infectivity inhibition assay using clade B (HXB2) env pseudotype virus (PV). The four compounds inhibited the entry of HIV HXB2 pseudotype viruses into target cells at 50% inhibitory concentrations (IC50) of 15.2 µM (9.7 µg/mL), 10.1 µM (7.5 µg/mL), 16.2 µM (12.7 µg/mL), and 21.6 µM (12.9 µg/mL), respectively. The interaction of these compounds with critical residues of the CD4-binding site of more than one clade of HIV gp120 and inhibition of HIV-1 entry into the target cell demonstrate the possibility of a new class of HIV entry inhibitors.

Hearing loss in Africa: current genetic profile.

Hearing impairment (HI) is highly heterogeneous with over 123 associated genes reported to date, mostly from studies among Europeans and Asians. Here, we performed a systematic review of literature on the genetic profile of HI in Africa. The study protocol was registered on PROSPERO, International Prospective Register of Systematic Reviews with the registration number "CRD42021240852". Literature search was conducted on PubMed, Scopus, Africa-Wide Information, and Web of Science databases. A total of 89 full-text records was selected and retrieved for data extraction and analyses. We found reports from only 17/54 (31.5%) African countries. The majority (61/89; 68.5%) of articles were from North Africa, with few reports found from sub-Saharan Africa. The most common method used in these publications was targeted gene sequencing (n = 66/111; 59.5%), and only 13.5% (n = 15/111) used whole-exome sequencing. More than half of the studies were performed in families segregating HI (n = 51/89). GJB2 was the most investigated gene, with GJB2: p.(R143W) founder variant only reported in Ghana, while GJB2: c.35delG was common in North African countries. Variants in MYO15A were the second frequently reported in both North and Central Africa, followed by ATP6V1B1 only reported from North Africa. Usher syndrome was the main syndromic HI molecularly investigated, with variants in five genes reported: USH2A, USH1G, USH1C, MYO7A, and PCDH15. MYO7A: p.(P1780S) founder variant was reported as the common Usher syndrome variant among Black South Africans. This review provides the most comprehensive data on HI gene variants in the largely under-investigated African populations. Future exomes studies particularly in multiplex families will likely provide opportunities for the discovery of the next sets of novel HI genes, and well as unreported variants in known genes to further our understanding of HI pathobiology, globally.

Egress of non-enveloped enteric RNA viruses.

A long-standing paradigm in virology was that non-enveloped viruses induce cell lysis to release progeny virions. However, emerging evidence indicates that some non-enveloped viruses exit cells without inducing cell lysis, while others engage both lytic and non-lytic egress mechanisms. Enteric viruses are transmitted via the faecal-oral route and are important causes of a wide range of human infections, both gastrointestinal and extra-intestinal. Virus cellular egress, when fully understood, may be a relevant target for antiviral therapies, which could minimize the public health impact of these infections. In this review, we outline lytic and non-lytic cell egress mechanisms of non-enveloped enteric RNA viruses belonging to five families: Picornaviridae, Reoviridae, Caliciviridae, Astroviridae and Hepeviridae. We discuss factors that contribute to egress mechanisms and the relevance of these mechanisms to virion stability, infectivity and transmission. Since most data were obtained in traditional two-dimensional cell cultures, we will further attempt to place them into the context of polarized cultures and in vivo pathogenesis. Throughout the review, we highlight numerous knowledge gaps to stimulate future research into the egress mechanisms of these highly prevalent but largely understudied viruses.

Full genomic characterization of a porcine rotavirus strain detected in an asymptomatic piglet in Accra, Ghana.

BACKGROUND: The introduction of rotavirus A vaccination across the developing world has not proved to be as efficacious as first hoped. One cause of vaccine failure may be infection by zoonotic rotaviruses that are very variable antigenically from the vaccine strain. However, there is a lack of genomic information about the circulating rotavirus A strains in farm animals in the developing world that may be a source of infection for humans. We therefore screened farms close to Accra, Ghana for animals sub-clinically infected with rotavirus A and then sequenced the virus found in one of these samples. RESULTS: 6.1% of clinically normal cows and pigs tested were found to be Rotavirus A virus antigen positive in the faeces. A subset of these (33.3%) were also positive for virus RNA. The most consistently positive pig sample was taken forward for metagenomic sequencing. This gave full sequence for all open reading frames except segment 5 (NSP1), which is missing a single base at the 5' end. The virus infecting this pig had genome constellation G5-P[7]-I5-R1-C1-M1-A8-N1-T7-E1-H1, a known porcine genotype constellation. CONCLUSIONS: Farm animals carry rotavirus A infection sub-clinically at low frequency. Although the rotavirus A genotype discovered here has a pig-like genome constellation, a number of the segments most closely resembled those isolated from humans in suspected cases of zoonotic transmission. Therefore, such viruses may be a source of variable gene segments for re-assortment with other viruses to cause vaccine breakdown. It is recommended that further human and pig strains are characterized in West Africa, to better understand this dynamic.

Distribution of rotavirus genotypes in the postvaccine introduction era in Ashaiman, Greater Accra Region, Ghana, 2014-2016.

Group A Rotaviruses (RVAs) are the most important etiological agents of acute gastroenteritis (AGE) in children less than 5 years of age. Mortality resulting from RVA gastroenteritis is higher in developing countries than in developed ones, causing a huge public health burden in global regions like Africa and South-East Asia. This study reports RVA genotypes detected in Ashaiman, Greater Accra Region, Ghana, in the postvaccine introduction era for the period 2014-2016. Stool samples were collected from children less than 5 years of age who visited Ashaiman Polyclinic with AGE from November 2014 to May 2015 and from December 2015 to June 2016. The samples were tested by enzyme immunoassay (EIA), and one-step multiplex reverse transcription polymerase chain reaction was performed on the EIA positive samples for gel-based binomial genotyping. Of the 369 stool samples collected from children with AGE, 145 (39%) tested positive by EIA. Five VP7 (G1, G3, G9, G10, and G12) and three VP4 (P[4], P[6] and P[8]) genotypes were detected. Eight G/P combinations were identified of which, G3P[6], G12P[8], G1P[8], and G9P[4] were the most prevalent and responsible for 93 (68%) of the AGE cases, and seven mixed-types were detected which represented 8% of the RVA cases. High prevalence, diversity, and mixed-types of RVAs were detected from Ashaiman with the emergence of unusual genotypes.

Haptoglobin phenotypes with weak antioxidant capacity increase risk factors of cardiovascular disease in Ghanaian HIV-infected patients on highly active antiretroviral therapy.

OBJECTIVE: Highly active antiretroviral therapy (HAART) has considerably reduced HIV/AIDS-related morbidity and mortality; however, the therapy has been associated with the development of cardiovascular disease (CVD), and genetic predisposition factors may aggravate disease outcome. This study was aimed at investigating the relationship between haptoglobin phenotypes and risk factors of CVD in HIV patients. METHODS: A total of 105 HIV sero-positive patients on HAART and 75 HIV-infected HAART-naïve individuals were enrolled in the study. Socio-demographics and clinical characteristics of the participants were obtained using a well-structured questionnaire. Lipid profile, lactate dehydrogenase (LDH) and haptoglobin (Hp) phenotypes were analysed from serum whiles haemoglobin (Hb) level, CD4+ cell count and HIV viral RNA load were determined using whole blood. RESULTS: Atherogenic index of plasma (AIP) was significantly higher in patients on HAART than the naïve group (P < 0.05). Age, BMI, visceral fat, systolic blood pressure LDH and lipid variables strongly and positively correlated with AIP (P < 0.05), with the exception of HDL-c (P < 0.001) which showed a negative correlation. HAART was associated with hypertension (χ2  = 4.33, P = 0.037), hypercholesterolaemia (χ2  = 10.99, P < 0.001), elevated LDL-c (χ2 = 10.30, P < 0.001) and decreased HDL-c (χ2  = 3.87, P = 0.09). Hp2-2 and Hp0 collectively was strongly associated with hypertension (OR = 2.54, P = 0.011), obesity (OR = 5.97, P < 0.001) and hypercholesterolaemia (OR = 2.99, P < 0.001). CONCLUSION: HIV/AIDS patients on HAART expressing Hp phenotypes with weak antioxidant capacity have an increased risk of developing CVD.

OBJECTIF: La thérapie antirétrovirale hautement active (HAART) a considérablement réduit la morbidité et la mortalité liées au VIH/SIDA; cependant, le traitement a été associé au développement de maladie cardiovasculaire (MCV) et des facteurs de prédisposition génétique pourraient aggraver l'évolution de la maladie. Cette étude visait à étudier la relation entre les phénotypes de l'haptoglobine et les facteurs de risque de MCV chez les patients VIH. MÉTHODES: Un total de 105 patients VIH positifs sous HAART et 75 personnes infectés par le VIH mais naïfs au HAART ont été recrutés pour l'étude. Les caractéristiques sociodémographiques et cliniques des participants ont été obtenues à l'aide d'un questionnaire bien structuré. Le profil lipidique, les phénotypes de la lactate déshydrogénase (LDH) et de l' haptoglobine (Hp) ont été analysés à partir du sérum tandis que le taux d'hémoglobine (Hb), la numération des cellules CD4+ et la charge d'ARN viral du VIH ont été déterminés en utilisant du sang total. RÉSULTATS: L'indice athérogène du plasma (IAP) était significativement plus élevé chez les patients sous HAART que chez le groupe naïf (p <0,05). Les variables âge, IMC, graisse viscérale, tension artérielle systolique, LDH et lipides étaient fortement et positivement corrélées à l'IAP (p < 0,05), à l'exception du HDL-c (p < 0,001) qui présentait une corrélation négative. L'HAART a été associée à l'hypertension (χ2 = 4,33; p = 0,037), l'hypercholestérolémie (χ2 = 10,99; p <0,001), une LDL-c élevée (χ2 = 10,30; p <0,001) et une diminution de HDL-c (χ2 = 3,87; p = 0,09). Ensemble, Hp2-2 et Hp0 étaient fortement associés à l'hypertension (OR = 2,54; p = 0,011), à l'obésité (OR = 5,97; p <0,001) et à l'hypercholestérolémie (OR = 2,99; p <0,001). CONCLUSION: Les patients VIH/SIDA sous HAART exprimant des phénotypes Hp à faible capacité antioxydante ont un risque accru de développer une maladie cardiovasculaire.

Characterisation of a rare, reassortant human G10P[14] rotavirus strain detected in Honduras.

BACKGROUND: Although first detected in animals, the rare rotavirus strain G10P[14] has been sporadically detected in humans in Slovenia, Thailand, United Kingdom and Australia among other countries. Earlier studies suggest that the strains found in humans resulted from interspecies transmission and reassortment between human and bovine rotavirus strains. OBJECTIVES: In this study, a G10P[14] rotavirus genotype detected in a human stool sample in Honduras during the 2010-2011 rotavirus season, from an unvaccinated 30-month old boy who reported at the hospital with severe diarrhea and vomiting, was characterised to determine the possible evolutionary origin of the rare strain. METHODS: For the sample detected as G10P[14], 10% suspension was prepared and used for RNA extraction and sequence independent amplification. The amplicons were sequenced by next-generation sequencing using the Illumina MiSeq 150 paired end method. The sequence reads were analysed using CLC Genomics Workbench 6.0 and phylogenetic trees were constructed using PhyML version 3.0. FINDINGS: The next generation sequencing and phylogenetic analyses of the 11-segmented genome of the G10P[14] strain allowed classification as G10-P[14]-I2-R2-C2-M2-A3-N2-T6-E2-H3. Six of the genes (VP1, VP2, VP3, VP6, NSP2 and NSP4) were DS-1-like. NSP1 and NSP5 were AU-1-like and NSP3 was T6, which suggests that multiple reassortment events occurred in the evolution of the strain. The phylogenetic analyses and genetic distance calculations showed that the VP7, VP4, VP6, VP1, VP3, NSP1, NSP3 and NSP4 genes clustered predominantly with bovine strains. NSP2 and VP2 genes were most closely related to simian and human strains, respectively, and NSP5 was most closely related to a rhesus strain. MAIN CONCLUSIONS: The genetic characterisation of the G10P[14] strain from Honduras suggests that its genome resulted from multiple reassortment events which were possibly mediated through interspecies transmissions.

Effectiveness of Monovalent and Pentavalent Rotavirus Vaccines in Guatemala.

BACKGROUND: Concerns remain about lower effectiveness and waning immunity of rotavirus vaccines in resource-poor populations. We assessed vaccine effectiveness against rotavirus in Guatemala, where both the monovalent (RV1; 2-dose series) and pentavalent (RV5; 3-dose series) vaccines were introduced in 2010. METHODS: A case-control evaluation was conducted in 4 hospitals from January 2012 to August 2013. Vaccine status was compared between case patients (children with laboratory-confirmed rotavirus diarrhea) and 2 sets of controls: nondiarrhea "hospital" controls (matched by birth date and site) and nonrotavirus "test-negative" diarrhea controls (adjusted for age, birth month/year, and site). Vaccine effectiveness ([1 - odds ratio of vaccination] × 100%) was computed using logistic regression models. RESULTS: We evaluated 213 case patients, 657 hospital controls, and 334 test-negative controls. Effectiveness of 2-3 doses of a rotavirus vaccine against rotavirus requiring emergency department visit or hospitalization was 74% (95% confidence interval [CI], 58%-84%) with hospital controls, and 52% (95% CI, 26%-69%) with test-negative controls. Using hospital controls, no significant difference in effectiveness was observed between infants 6-11 months (74% [95% CI, 18%-92%]) and children ≥12 months of age (71% [95% CI, 44%-85%]) (P= .85), nor between complete courses of RV1 (63% [95% CI, 23%-82%]) and RV5 (69% [95% CI, 29%-87%]) (P= .96). An uncommon G12P[8] strain, partially heterotypic to strains in both vaccines, was identified in 89% of cases. CONCLUSIONS: RV1 and RV5 were similarly effective against severe rotavirus diarrhea caused by a heterotypic strain in Guatemala. This supports broader implementation of rotavirus vaccination in low-income countries where >90% global deaths from rotavirus occur.

Clinical outcomes and immunological response to SARS-CoV-2 infection among people living with HIV.

People living with HIV (PLWH) usually suffer from co-infections and co-morbidities including respiratory tract infections. SARS-CoV-2 has been reported to cause respiratory infections. There are uncertainties in the disease severity and immunological response among PLWH who are co-infected with COVID-19. This review outlines the current knowledge on the clinical outcomes and immunological response to SARS-CoV-2 among PLWH. Literature was searched in Google scholar, Scopus, PubMed, and Science Direct conforming with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines from studies published from January 2020 to June 2023. A total of 81 studies from 25 countries were identified, and RT-PCR was used in confirming COVID-19 in 80 of the studies. Fifty-seven studies assessed risk factors and clinical outcomes in HIV patients co-infected with COVID-19. Thirty-nine of the studies indicated the following factors being associated with severe outcomes in HIV/SARS-CoV-2: older age, the male sex, African American race, smoking, obesity, cardiovascular diseases, low CD4+ count, high viral load, tuberculosis, high levels of inflammatory markers, chronic kidney disease, hypertension, diabetes, interruption, and delayed initiation of ART. The severe outcomes are patients' hospitalization, admission at intensive care unit, mechanical ventilation, and death. Twenty (20) studies, however, reported no difference in clinical presentation among co-infected compared to mono-infected individuals. Immune response to SARS-CoV-2 infection was investigated in 25 studies, with some of the studies reporting high levels of inflammatory markers, T cell exhaustion and lower positive conversion rate of IgG in PLWH. There is scanty information on the cytokines that predisposes to severity among HIV/SARS-CoV-2 co-infected individuals on combined ART. More research work should be carried out to validate co-infection-related cytokines and/or immune markers to SARS-CoV-2 among PLWH.

Development and utility of a SARS-CoV-2 pseudovirus assay for compound screening and antibody neutralization assays.

Background: The highly infectious nature of SARS-CoV-2 necessitates using bio-containment facilities to study viral pathogenesis and identify potent antivirals. However, the lack of high-level bio-containment laboratories across the world has limited research efforts into SARS-CoV-2 pathogenesis and the discovery of drug candidates. Previous research has reported that non-replicating SARS-CoV-2 Spike-pseudotyped viral particles are effective tools to screen for and identify entry inhibitors and neutralizing antibodies. Methods: To generate SARS-CoV-2 pseudovirus, a lentiviral packaging plasmid p8.91, a luciferase expression plasmid pCSFLW, and SARS-CoV-2 Spike expression plasmids (Wild-type (D614G) or Delta strain) were co-transfected into HEK293 cells to produce a luciferase-expressing non-replicating pseudovirus which expresses SARS-CoV-2 spike protein on the surface. For relative quantitation, HEK293 cells expressing ACE2 (ACE2-HEK293) were infected with the pseudovirus, after which luciferase activity in the cells was measured as a relative luminescence unit. The ACE2-HEK293/Pseudovirus infection system was used to assess the antiviral effects of some compounds and plasma from COVID-19 patients to demonstrate the utility of this assay for drug discovery and neutralizing antibody screening. Results: We successfully produced lentiviral-based SARS-CoV2 pseudoviruses and ACE2-expressing HEK293 cells. The system was used to screen compounds for SARS-CoV-2 entry inhibitors and identified two compounds with potent activity against SARS-CoV-2 pseudovirus entry into cells. The assay was also employed to screen patient plasma for neutralizing antibodies against SARS-CoV-2, as a precursor to live virus screening, using successful hits. Significance: This assay is scalable and can perform medium-to high-throughput screening of antiviral compounds with neither severe biohazard risks nor the need for higher-level containment facilities. Now fully deployed in our resource-limited laboratory, this system can be applied to other highly infectious viruses by swapping out the envelope proteins in the plasmids used in pseudovirus production.

Sensitive and specific quantitative detection of rotavirus A by one-step real-time reverse transcription-PCR assay without antecedent double-stranded-RNA denaturation.

A real-time quantitative reverse transcription-PCR (qRT-PCR) assay using the recombinant thermostable Thermus thermophilus (rTth) enzyme was developed to detect and quantify rotavirus A (RVA). By using rTth polymerase, significant improvement was achieved over the existing real-time RT-PCR assays, which require denaturation of the RVA double-stranded RNA (dsRNA) prior to assay setup. Using a dsRNA transcript for segment 7, which encodes the assay target NSP3 gene, the limit of detection for the improved assay was calculated to be approximately 1 genome copy per reaction. The NSP3 qRT-PCR assay was validated using a panel of 1,906 stool samples, 23 reference RVA strains, and 14 nontarget enteric virus samples. The assay detected a diverse number of RVA genotypes and did not detect other enteric viruses, demonstrating analytical sensitivity and specificity for RVA in testing stool samples. A XenoRNA internal process control was introduced and detected in a multiplexed qRT-PCR format. Because it does not require an antecedent dsRNA denaturation step, this assay reduces the possibility of sample cross-contamination and requires less hands-on time than other published qRT-PCR protocols for RVA detection.

Two rotavirus outbreaks caused by genotype G2P[4] at large retirement communities: cohort studies.

BACKGROUND: Outbreaks of rotavirus gastroenteritis in elderly adults are reported infrequently but are often caused by G2P[4] strains. In 2011, outbreaks were reported in 2 Illinois retirement facilities. OBJECTIVE: To implement control measures, determine the extent and severity of illness, and assess risk factors for disease among residents and employees. DESIGN: Cohort studies using surveys and medical chart abstraction. SETTING: Two large retirement facilities in Cook County, Illinois. PATIENTS: Residents and employees at both facilities and community residents with rotavirus disease. MEASUREMENTS: Attack rates, hospitalization rates, and rotavirus genotype. RESULTS: At facility A, 84 of 324 residents (26%) were identified with clinical or laboratory-confirmed rotavirus gastroenteritis (median age, 84 years) and 11 (13%) were hospitalized. The outbreak lasted 7 weeks. At facility B, 90 case patients among 855 residents (11%) were identified (median age, 88 years) and 19 (21%) were hospitalized. The facility B outbreak lasted 9.3 weeks. Ill employees were identified at both locations. In each facility, attack rates seemed to differ by residential setting, with the lowest rates among those in more separated settings or with high baseline level of infection control measures. The causative genotype for both outbreaks was G2P[4]. Some individuals shed virus detected by enzyme immunoassay or genotyping reverse transcription polymerase chain reaction for at least 35 days. G2P[4] was also identified in 17 of 19 (89%) samples from the older adult community but only 15 of 40 (38%) pediatric samples. LIMITATION: Medical or cognitive impairment among residents limited the success of some interviews. CONCLUSION: Rotavirus outbreaks can occur among elderly adults in residential facilities and can result in considerable morbidity. Among older adults, G2P[4] may be of unique importance. Health professionals should consider rotavirus as a cause of acute gastroenteritis in adults. PRIMARY FUNDING SOURCE: None.

Analysis of dengue fever disease in West Africa.

Dengue fever disease (DFD) which is caused by four antigenically distinct dengue viruses (DENV) presents a global health threat, with tropical and subtropical regions at a greater risk. The paucity of epidemiological data on dengue in West African subregion endangers efforts geared toward disease control and prevention. A systematic search of DFD prevalence, incidence, and DENV-infected Aedes in West Africa was conducted in PubMed, Scopus, African Index Medicus, and Google Scholar in line with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. A total of 58 human prevalence studies involving 35,748 people from 8 countries were identified. Two incidence and six DENV-infected studies were also reviewed. Nigeria and Burkina Faso contributed the majority of the prevalence studies which spanned between 1968 and 2018, with a considerable variation in coverage among the countries reviewed in this study. An average prevalence of 20.97% was observed across both general prevalence and acute DENV infection study categories, ranging between 0.02% and 93%. The majority of these studies were conducted in acute febrile patients with a prevalence range of 0.02-93% while 19% (n = 11) of all studies were general population-based studies and reported a prevalence range of 17.2-75.8%. DENV-infected Aedes aegypti were reported in four out of the five countries with published reports; with DENV-2 found circulating in Cape Verde, Senegal, and Burkina Faso while DENV-3 and DENV-4 were also reported in Senegal and Cape Verde, respectively. High prevalence of DFD in human populations and the occurrence of DENV-infected A. aegypti have been reported in West Africa, even though weaknesses in study design were identified. Epidemiological data from most countries and population in the subregion were scarce or non-existent. This study highlights the epidemic risk of DFD in West Africa, and the need for research and surveillance to be prioritized to fill the data gap required to enact effective control measures.