The Development of Epitope-Based Recombinant Protein Vaccines against SARS-CoV-2.

The COVID-19 pandemic continues to cause infections and deaths, which are attributable to the SARS-CoV-2 Omicron variant of concern (VOC). Moderna's response to the declining protective efficacies of current SARS-CoV-2 vaccines against Omicron was to develop a bivalent booster vaccine based on the Spike (S) protein from the Wuhan and Omicron BA.4/BA.5 strains. This approach, while commendable, is unfeasible in light of rapidly emerging mutated viral strains. PubMed and Google Scholar were systematically reviewed for peer-reviewed papers up to January 2024. Articles included focused on specific themes such as the clinical history of recombinant protein vaccine development against different diseases, including COVID-19, the production of recombinant protein vaccines using different host expression systems, aspects to consider in recombinant protein vaccine development, and overcoming problems associated with large-scale recombinant protein vaccine production. In silico approaches to identify conserved and immunogenic epitopes could provide broad protection against SARS-CoV-2 VOCs but require validation in animal models. The recombinant protein vaccine development platform has shown a successful history in clinical development. Recombinant protein vaccines incorporating conserved epitopes may utilize a number of expression systems, such as yeast (Saccharomyces cerevisiae), baculovirus-insect cells (Sf9 cells), and Escherichia coli (E. coli). Current multi-epitope subunit vaccines against SARS-CoV-2 utilizing synthetic peptides are unfeasible for large-scale immunizations. Recombinant protein vaccines based on conserved and immunogenic proteins produced using E. coli offer high production yields, convenient purification, and cost-effective production of large-scale vaccine quantities capable of protecting against the SARS-CoV-2 D614G strain and its VOCs.

Immunogenicity of trivalent DNA vaccine candidate encapsulated in Chitosan-TPP nanoparticles against EV-A71 and CV-A16.

Aim: To develop a trivalent DNA vaccine candidate encapsulated in Chitosan-TPP nanoparticles against hand foot and mouth disease (HFMD) and assess its immunogenicity in mice.Materials & methods: Trivalent plasmid carrying the VP1 and VP2 genes of EV-A71, VP1 gene of CV-A16 was encapsulated in Chitosan-TPP nanoparticles through ionic gelation. In vitro characterization and in vivo immunization studies of the CS-TPP-NPs (pIRES-VP121) were performed.Results: Mice administered with CS-TPP NPs (pIRES-VP121) intramuscularly were observed to have the highest IFN-γ response. Sera from mice immunized with the naked pDNA and CS-TPP-NPs (pIRES-VP121) demonstrated good viral clearance against wild-type EV-A71 and CV-A16 in RD cells.Conclusion: CS-TPP-NPs (pIRES-VP121) could serve as a prototype for future development of multivalent HFMD DNA vaccine candidates.

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Enhanced-nitrogen removal through Fe(III)-triggered partial dissimilatory nitrate reduction to ammonium coupling with anammox in anammox bioreactor.

Anammox is recognized as a prospective alternative for future biological nitrogen removal technologies. However, the nitrate by-products produced by anammox bacteria limit its overall nitrogen removal efficiency below 88 %. This study introduced Fe(III) into the anammox bioreactor to enhance the nitrogen removal efficiency to approximately 95 %, surpassing the biochemical limit of 88 % imposed by anammox stoichiometry. Anammox sludge was demonstrated to utilize extracellular polymeric substances to reduce Fe(III) into Fe(II), and this process promoted the dominance of Ca. Brocadia. The iron addition improved the abundance of narGHI genes and facilitated the partial dissimilatory nitrate reduction to ammonium, with nitrite as the end product. The accumulated nitrite was then eliminated through the anammox pathway, along with the excess ammonium (30 mg/L) in the influent. Overall, this study deepens our understanding of the enhanced nitrogen removal triggered by Fe(III) in anammox sludge and offers an effective approach to boost anammox process.

The Utility of a Novel Neuropsychological Measurement to Analyze Event-Related Attentional Behaviors among Young Children with Attention Deficit Hyperactivity Disorder-a Pilot Study.

OBJECTIVE: The identification and diagnosis of children with attention deficit hyperactivity disorder (ADHD) traits is challenging during the preschool stage. Neuropsychological measures may be useful in early assessments. Furthermore, analysis of event-related behavior appears to be an unmet need for clinical treatment planning. Conners' Kiddie Continuous Performance Test (K-CPT) is the most popular well-established neuropsychological measurement but lacks event markers to clarify the heterogeneous behaviors among children. This study utilized a novel commercially available neuropsychological measure, the ΣCOG, which was more game-like and provided definite event markers of individual trial in the test. METHODS: Thirty-three older preschool children (14 were diagnosed with ADHD, mean age: 66.21 ± 5.48 months; 19 demonstrated typical development, mean age: 61.16 ± 8.11 months) were enrolled and underwent comprehensive medical and developmental evaluations. All participants underwent 2 versions of neuropsychological measures, including the K-CPT, Second Edition (K-CPT 2) and the ΣCOG, within a short interval. RESULTS: The study indicated the omissions and response time scores measured in this novel system correlated with clinical measurement of the behavioral scales in all participants and in the group with ADHD; additionally, associations with the traditional K-CPT 2 were observed in commissions and response time scores. Furthermore, this system provided a within-task behavioral analysis that identified the group differences in the specific trial regarding omission and commission errors. CONCLUSIONS: This innovative system is clinically feasible and can be further used as an alternative to the K-CPT 2 especially in research by revealing within-task event-related information analysis.

Identification and Validation of Peptides Specifying SARS-CoV-2 B-Cell Epitopes Eliciting Neutralizing Antibodies.

Vaccination is an effective means of inducing immune protection to prevent transmissible diseases. During the Covid-19 pandemic, immunizations using traditional and novel vaccine platforms such as the inactivated SARSCo-V-2 vaccine, adenoviral-vectored, and nucleic acid-based mRNA vaccines have been relatively successful in controlling the rates of infection and hospitalizations. Nevertheless, the danger posed by the emergence of SARS-CoV-2 variants would set the stage for the design of next generation vaccines. To overcome the lack of efficacy of current vaccines against emerging SARS-CoV-2 variants, new vaccines must be able to overcome the reduced effectiveness of the current vaccines. Since the current Covid-19 vaccines are dependent on the whole S-protein of Wuhan strain as the antigen, mutations have rendered the current Covid-19 vaccines less effective against variants of concern (VoCs). Instead of using the whole S-protein, peptide-based epitopes could be predicted using immunoinformatic approaches, simulation of the 3D structures, overlapping peptides covering the whole length of the S-protein or peptide arrays based on synthetic peptide combinatorial libraries comprising peptides recognizable by monoclonal antibodies. B-cell epitopes were predicted, and immunogenicity of peptides was validated in mice by immunizing mice with peptides conjugated to keyhole limpet hemocyanin (KLH) mixed with Montanide 51 as an adjuvant. The immunogenicity of epitopes that could elicit peptide specific IgGs was determined by peptide-based ELISA. Neutralizing activities were determined by cPass and pseudovirus-based neutralization assays.

Caries trajectories from childhood to adolescence: Analysis of data from a nationwide school dental service.

OBJECTIVES: The aim of the study was to assess patterns of longitudinal changes in caries status among school-going children in Singapore. METHODS: Dental records for a single cohort of students who received dental examinations in six standard examination years between 2009 and 2017 were analysed (n = 24 699). Group-based trajectory modelling with a zero-inflated Poisson distribution was carried out to determine dental caries trajectories in the permanent dentition. Associations between sociodemographic factors and trajectory group membership were assessed using multinomial logistic regression. RESULTS: The predicted population distribution across the four caries trajectory groups identified was 65.0% ('none'), 16.8% ('low'), 14.8% ('medium') and 3.4% ('high'). The 'none' trajectory group had a decayed, missing and filled teeth (DMFT) score of 0 throughout the 8 years. Higher baseline DMFT counts and nonlinear increases in DMFT scores were noted for the 'low', 'medium' and 'high' trajectory groups. The correlation coefficient between DMFT counts in years 6 and 8 was 0.91, as compared to 0.77 between baseline and year 1. Factors associated with the 'high' caries trajectory include lower socio-economic status, female gender, Chinese race (compared to the Indian race), enrolment in primary schools in the Eastern and Western regions of Singapore, and enrolment in public secondary schools. CONCLUSIONS: Under a nationwide school dental service, four trajectory patterns of caries counts in the permanent dentition were identified over 8 years. Among students in the 'low', 'medium' and 'high' trajectory groups, greater caries increment was noted during the transition from primary to secondary school. The correlation between DMFT counts in successive examinations was stronger in older than younger ages.

Identification and Genomic Characterization of Two Novel Hepatoviruses in Shrews from Yunnan Province, China.

Hepatitis A virus (HAV), a member of the genus Hepatovirus (Picornaviridae HepV), remains a significant viral pathogen, frequently causing enterically transmitted hepatitis worldwide. In this study, we conducted an epidemiological survey of HepVs carried by small terrestrial mammals in the wild in Yunnan Province, China. Utilizing HepV-specific broad-spectrum RT-PCR, next-generation sequencing (NGS), and QNome nanopore sequencing (QNS) techniques, we identified and characterized two novel HepVs provisionally named EpMa-HAV and EpLe-HAV, discovered in the long-tailed mountain shrew (Episoriculus macrurus) and long-tailed brown-toothed shrew (Episoriculus leucops), respectively. Our sequence and phylogenetic analyses of EpMa-HAV and EpLe-HAV indicated that they belong to the species Hepatovirus I (HepV-I) clade II, also known as the Chinese shrew HepV clade. Notably, the codon usage bias pattern of novel shrew HepVs is consistent with that of previously identified Chinese shrew HepV. Furthermore, our structural analysis demonstrated that shrew HepVs differ from other mammalian HepVs in RNA secondary structure and exhibit variances in key protein sites. Overall, the discovery of two novel HepVs in shrews expands the host range of HepV and underscores the existence of genetically diverse animal homologs of human HAV within the genus HepV.

Cost-Effectiveness of a Home Telemonitoring System for Asian Adults with Type 2 Diabetes Mellitus.

Background: Telemonitoring programs have been found to be effective in improving diabetic control by promoting patients' self-management of diabetes through medication adherence, dietary modifications, and exercise. Nonetheless, few studies have assessed the cost-effectiveness of telemonitoring for the self-management of diabetes based on real-world data. Methods: A randomized controlled trial entitled Optimizing care of Patients via Telehealth In Monitoring and Augmenting their control of Diabetes Mellitus was conducted among adults with Type 2 Diabetes Mellitus in Singapore. Individuals in the intervention group (n = 159) underwent a telemonitoring program comprising of remote patient monitoring, education, individualized health coaching, and teleconsultations, whereas individuals in the control group (n = 160) received regular care. Economic evaluation was conducted from health care system and societal perspectives in 2020 in Singapore dollars, using health outcomes and costs documented at baseline and at 6 month follow-up. One-way sensitivity analyses and bootstrapping to generate scatter plot on cost-effectiveness planes were done. Results: The adjusted reduction in HbA1c scores was greater in the intervention group by -0.41 (95% confidence interval [CI], -0.65 to -0.17), while the change in utility scores was higher in the intervention group by 0.011 (95% CI, -0.016 to 0.0378). From a health care perspective, the incremental cost-effectiveness ratio (ICER) of the telemonitoring program per unit improvement in HbA1c, per additional case of well-controlled diabetes, and per unit improvement in quality adjusted life years was SGD 580.44, SGD 9100.15, and SGD 21,476.36, respectively. From a societal perspective, the ICERs were SGD 817.20, SGD 12,812.02, and SGD 30,236.36, respectively. Conclusions: The Optimizing care of Patients via Telehealth In Monitoring and Augmenting their control of Diabetes Mellitus telemonitoring program was effective and potentially cost-effective for the management and control of diabetes among patients in primary care.

Conceptualising TMD symptom burden in youths: Symptom duration, frequency, intensity and interference.

OBJECTIVE: This study aimed to conceptualise Temporomandibular disorder (TMD) symptom burden and severity and explored their interrelationships with somatic symptoms and psychological distress. METHODS: Participants were recruited from a local polytechnic. The quintessential five TMD symptoms (5Ts) of the Diagnostic Criteria for TMDs (DC/TMD) were appraised and extended to evaluate the duration, frequency, intensity and interference of discrete TMD symptoms. Global TMD severity (GS) was computed by totaling the points for all TMD symptoms and dimensions. TMD (TS) and somatic symptom (SS) burden were assessed based on the Somatic Symptoms Scale-8, while psychological distress was measured with the Depression, Anxiety and Stress Scales-21. Statistical analyses were performed using Kruskal-Wallis/Dunn tests and Spearman's correlation (α = .05). RESULT: Of the 366 eligible participants (mean age 19.1 ± 2.3 years), 51.4% were 5Ts-negative and 48.6% were 5Ts-positive. Among the 5Ts-positive individuals, 25.3%/64.0% were 'bothered a little' whereas 4.5%/10.7% were 'bothered a lot' by TMD pain/headache. Correspondingly, 32.6%/12.4%/5.1% were 'bothered a little' while 2.8%/2.8%/1.1% were 'bothered a lot' by TMJ sounds/closed/open locking. TS burden was moderate-to-strongly correlated to aggregate symptom duration, frequency, intensity, interference, GS and SS burden (rs = .50-.88). While TS burden and GS were weakly associated with psychological distress (rs = .18-.36), SS burden was moderately related to depression, anxiety and stress (rs = .47-.53). CONCLUSIONS: TS burden can serve as a proxy for global TMD severity and may be more meaningful than the mere presence of TMD symptoms in clinical and research settings.

Impact of income and financial subsidies on oral health care utilization among persons with disabilities in Singapore.

BACKGROUND/AIM(S): Globally, studies have shown that the dental disease burden among persons with intellectual and/or developmental disabilities (IDD) is high and can be attributed to lower utilization levels of dental services. The aim of the study was to assess the influence of income and financial subsidies on the utilization of dental care services among persons with IDD in Singapore. METHODS: Between August 2020 and August 2021, a cross-sectional study was conducted via centres offering Early Intervention Programme for Infants and Children, special education schools and adult associations in Singapore serving persons with IDD. A sample of 591 caregivers of children and adults with IDD completed the survey. Data on sociodemographic information, oral health behaviours and dental utilization were collected. Financial subsidy status was assessed by the uptake of a government-funded, opt-in Community Health Assist Scheme (CHAS) for low-income families that provided a fixed subsidy amount for dental services in the primary care setting. Statistical analysis was carried out using univariable, multiple logistic regression and modified Poisson regression. Propensity score matching was carried out in R version 4.0.2 to assess the impact of financial subsidies on oral health care utilization among persons with IDD. RESULTS: Compared to those with lower gross monthly household incomes, the adjusted prevalence ratios of having at least one dental visit in the past year, having at least one preventive dental visit in the past year, and visiting the dentist at least once a year for persons with IDD with gross monthly household incomes of above SGD$4000 were 1.28 (95% CI 1.08-1.52), 1.48 (95% CI 1.14-1.92) and 1.36 (95% CI 1.09-1.70), respectively. Among those who were eligible for CHAS Blue subsidies (247 participants), 160 (62.0%) took up the CHAS Blue scheme and 96 (35.4%) visited the dentist at least yearly. There was no statistically significant difference in the utilization of dental services among individuals enrolled in the CHAS Blue subsidy scheme among those eligible for CHAS Blue subsidies. CONCLUSION: Higher household income was associated with a higher prevalence of dental visits in the past year, preventive dental visits in the past year, and at least yearly dental visits. CHAS Blue subsidies alone had limited impact on dental utilization among persons with IDD who were eligible for subsidies.