In the tropics and subtropics climates worldwide, the dengue virus (DENV) is the most common of arboviruses and a significant public health threat. The severe disease usually occurs during the primary infection, but more serious cases begin after the second instance of infection with a different serotype. Humans' innate immune system is composed of monocytes, macrophages, and dendritic cells, and they are capable of mounting rapid inflammatory responses. These cells are also called primary antigen-presenting cells, and they are essential for the formation of the immune system's long-term memory mechanisms. Through scientific advances, valuable knowledge into the pathogenesis of more serious diseases, and new methods to the production of dengue vaccines and antiviral drugs have been provided. We summarized details in the current literature review, including references, abstracts, and full text of journal articles. So that, we tried to review all available studies that projected existing awareness about the immune response to the dengue virus and the current status of the vaccine. Such information was selected and extracted from the PubMed, Web of Science, and Google Scholar databases for published data from 2000 to 2020 using relevant keywords containing a combination of terms, including dengue fever, epidemiology, clinical manifestation, immune response, and vaccine.

To assess the prevalence, temporal trends, and diagnostic concordance of transfusion-transmitted viruses (TTVs) using combined serological and nucleic acid testing (NAT) in a large donor population in Jeddah, Saudi Arabia. This retrospective study analysed all blood donations screened from 2019 to 2024 at King Fahad Armed Forces Hospital, using serological assays and NAT. Prevalence estimates were calculated with 95% confidence intervals. Temporal trends were evaluated using generalised estimating equations logistic regression. Multivariable logistic regression identified predictors of Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) positivity. Diagnostic agreement between serology and NAT was assessed using Cohen’s kappa statistic. Among 48,151 donors, seroprevalence was 0.4% for HBsAg, 0.3% for HCV Ab, 0.1% for HIV Ab, and 0.02% for HTLV Ab. HBc Ab was detected in 4.7%. NAT identified HBV and HCV in 0.2% and 0.1%, respectively. Logistic regression showed a significant annual decline in HBsAg and NAT-HBV. Older age and non-Saudi nationality were linked to higher HBsAg and HCV positivity. Concordance between serology and NAT was substantial for HIV but negligible for HBV and HCV. TTVs rates are low and declining, but HBV/HCV concordance underscores the need for continued dual testing to ensure transfusion safety.

Background/Objectives: Early and accurate quantification of Human Immunodeficiency Virus type 1 (HIV-1) viral load is essential for monitoring antiretroviral therapy and guiding clinical management. Although conventional real-time polymerase chain reaction (PCR) platforms provide reliable viral load measurement, they often require centralized laboratories and longer turnaround times. Cartridge-based systems such as the GeneXpert HIV-1 Viral Load assay offer a simplified testing workflow and may facilitate decentralized molecular testing. This study aimed to evaluate the qualitative and quantitative agreement between the GeneXpert HIV-1 Viral Load assay and the Abbott Alinity m HIV-1 assay. Methods: A total of 102 residual clinical Ethylenediaminetetraacetic acid (EDTA) plasma specimens were analyzed using both the GeneXpert HIV-1 Viral Load assay and the Abbott Alinity m HIV-1 assay. Qualitative agreement was evaluated using positive percent agreement (PPA), negative percent agreement (NPA), overall agreement, and Cohen’s κ coefficient. Quantitative agreement among specimens with paired quantifiable viral load results was assessed using Pearson’s correlation and Bland–Altman analyses. Results: Overall qualitative agreement between the two assays was 95.1%, with a PPA of 92.6%, an NPA of 100.0%, and a Cohen’s κ coefficient of 0.894, indicating almost perfect agreement. Among the 57 specimens with paired quantifiable viral load results, a very strong positive correlation was observed (Pearson’s r = 0.9972; 95% CI: 0.9952–0.9984; p < 0.001). Bland–Altman analysis demonstrated a minimal mean bias of −0.018 log₁₀ IU/mL, with 95% limits of agreement ranging from −0.175 to 0.139 log₁₀ International Units per milliliter (IU/mL). All paired quantitative differences were within the clinically accepted agreement threshold of ±0.5 log₁₀ IU/mL. Conclusions: The GeneXpert HIV-1 Viral Load assay demonstrated excellent qualitative and quantitative agreement with the Abbott Alinity m HIV-1 assay. These findings support the potential use of the GeneXpert HIV-1 Viral Load assay as an alternative testing platform for routine HIV-1 viral load monitoring in appropriate clinical settings.

The zoonotic potential of bat coronaviruses, especially HKU5, is a significant issue because of their capacity to utilize human angiotensin-converting enzyme 2 (ACE2) as a receptor for cellular entry. This study offers structural insights into the binding kinetics of HKU5 (Bat Merbecovirus HKU5) receptor-binding domain (RBD) spike protein with human ACE2 through a multiscale computational method. This study employed structural modeling, 300-nanosecond (ns) molecular dynamics (MD) simulations, alanine-scanning mutagenesis, and computational peptide design to investigate ACE2 recognition by the HKU5 RBD and its interactions with peptides. The root mean square deviation (RMSD) investigation of HKU5–ACE2 complexes indicated that HKU5 exhibited greater flexibility than SARS-CoV-2, with RMSD values reaching a maximum of 1.2 nm. Free energy analysis, Molecular Mechanics/Generalized Born Surface Area (MM/GBSA), indicated a more robust binding affinity of HKU5 to ACE2 (ΔG_Total = −21.61 kcal/mol) in contrast to SARS-CoV-2 (ΔG_Total = −5.82 kcal/mol), implying that HKU5 binding with ACE2 had higher efficiency. Additionally, a peptide was designed from the ACE2 interface, resulting in the development of 380 single-site mutants by mutational alterations. The four most promising mutant peptides were selected for 300-nanosecond (ns) MD simulations, subsequently undergoing quantum chemical calculations (DFT) to evaluate their electronic characteristics. MM/GBSA of −37.83 kcal/mol indicated that mutant-1 exhibits the most favorable binding with HKU5, hence potentially inhibiting ACE2 interaction. Mutant-1 formed hydrogen bonds involving Glu74, Ser202, Ser204, and Asn152 residues of HKU5. Finally, QM/MM calculations on the peptide–HKU5 complexes showed the most favorable ΔE_interaction of −170.47 (Hartree) for mutant-1 peptide. These findings offer a thorough comprehension of receptor-binding dynamics and are crucial for evaluating the zoonotic risk associated with HKU5-CoV and guiding the design of receptor-targeted antiviral treatments.