The appropriate host cell immune responses for the progression of several diseases, including gastric or stomach cancer (GC), are significantly influenced by HLA polymorphisms. Our objective was to systematically review the evidence linking HLA polymorphisms with the risk of Helicobacter. pylori related GC. We conducted a comprehensive literature search to identify studies published between 2000 and April 2023 on the association of HLA polymorphisms with H. pylori related GC using databases such as Medline through PubMed, Embase, Web of Science (core collection), The Cochrane Library, and Scopus. Two authors independently screened articles, extracted data, and assessed the risk of bias using the Risk of Bias Assessment tool for Non‐randomized Studies. From 7872 retrieved studies, 19 met inclusion criteria, encompassing 1656 cases and 16,787 controls across four World Health Organization regions, with Japan contributing the most studies. We explored HLA‐A/B/C, HLA‐DRB1/DQA1/DQB1, HLA‐G, and MICA alleles. Of 29 significant HLA polymorphisms identified, 18 showed a positive association with GC, whereas 11 were negatively associated. HLA‐DQB1*06 allele was most frequently associated to susceptibility, as reported in four studies, followed by HLA‐DRB1*04 and HLA‐DQA1*01, each reported in two studies. Conversely, HLA‐G*01, HLA‐DQA1*01, HLA‐DQA1*05, and HLA‐DQB1*03 were identified as protective in two studies each. Additionally, five genotypes and six haplotypes were reported as positive, whereas three genotypes and two haplotypes were negative factors for the disease incidence or mortality. Despite heterogeneity in the study population and types of HLA polymorphisms examined, our analysis indicates certain polymorphisms are associated with H. pylori related GC progression and mortality in specific populations.

Treatment of carbapenem-resistant Acinetobacter baumannii (CRAb) infections has become a significant challenge for physicians due to its resistance to common antibiotics. Colistin, previously banned, has been reintroduced despite debates about its effectiveness and safety. We aimed to synthesize evidence on the effectiveness of Colistin in the CRAb infection management, based on current literature. We conducted a comprehensive search to identify relevant studies on the effectiveness of Colistin in treating CRAb infection in major databases such as Medline through PubMed, Embase, Web of Science, The Cochrane Library, and Scopus. We did not limit the search by age of participants, sex, region, or year of publication, but we only included randomized controlled trials (RCTs), quasi-experimental studies, cohort studies, case-control studies, and cross-sectional studies published in English, which had at least one comparison control group. Two independent authors screened articles, extracted data, and assessed the risk of bias in selected articles using the RoBANS tool. Our search retrieved 7907 articles, of which five were included after the sequential screening. All five studies were retrospective case-control studies from five different countries, with a total of 776 participants. Two studies showed a lower mortality rate in the intervention (Colistin) group as the primary outcome, whereas two studies showed the opposite mortality trend. One study reported a higher rate of infection remission in the intervention group, but the result was not statistically significant. Our systematic review could not find any robust evidence to support the effectiveness of Colistin over commonly used antibiotics. Due to the large discrepancy among the primary outcomes of the included studies, we recommend further randomized controlled trials with a larger number of participants to determine the suitability of Colistin for treating CRAb infections.

Background: An effective vaccine against Nipah virus (NiV) is crucial due to its high fatality rate and recurrent outbreaks in South and Southeast Asia. Vaccine development is challenged by the lack of validated accessible neutralization assays, as virus culture requires BSL-4 facilities, restricting implementation in resource-limited settings. To address this, we standardized and validated a pseudotyped virus neutralization assay (PNA) for assessing NiV-neutralizing antibodies in BSL-2 laboratories. Methods: The NiV-PNA was validated following international regulatory standards, using a replication-defective recombinant Vesicular stomatitis virus (rVSV) backbone dependent pseudotyped virus. Assessments included sensitivity, specificity, dilutional linearity, relative accuracy, precision, and robustness. The assay was calibrated using the WHO International Standard for anti-NiV antibodies and characterized reference sera to ensure reliable performance. Findings: Preliminary evaluation of the developed NiV-PNA showed 100% sensitivity and specificity across 10 serum samples (5 positive, 5 negative), with a positive correlation to a calibrated reference assay (R² = 0.8461). Dilutional linearity (R² = 0.9940) and accuracy (98.18%) were confirmed across the analytical titer range of 11-1728 IU/mL. The assay also exhibited high precision, with intra-assay and intermediate precision geometric coefficients of variation of 6.66% and 15.63%, respectively. Robustness testing demonstrated minimal variation across different pseudotyped virus lots, incubation times, and cell counts. Conclusions: The validated NiV-PNA is a reproducible and scalable assay platform for quantifying NiV neutralizing antibodies, offering a safer alternative to virus culture. Its validation and integration into the CEPI Centralized Laboratory Network will enhance global capacity for vaccine evaluation and outbreak preparedness.

Background: An effective vaccine against Nipah virus (NiV) is crucial due to its high fa-tality rate and recurrent outbreaks in South and Southeast Asia. Vaccine development is challenged by the lack of validated accessible neutralization assays, as virus culture re-quires BSL-4 facilities, restricting implementation in resource-limited settings. To address this, we standardized and validated a pseudotyped virus neutralization assay (PNA) for assessing NiV-neutralizing antibodies in BSL-2 laboratories. Methods: The NiV-PNA was validated following international regulatory standards, us-ing a replication-defective recombinant Vesicular stomatitis virus (rVSV) backbone de-pendent pseudotyped virus. Assessments included sensitivity, specificity, dilutional line-arity, relative accuracy, precision, and robustness. The assay was calibrated using the WHO International Standard for anti-NiV antibodies and characterized reference sera to ensure reliable performance. Findings: The developed NiV-PNA showed 100% sensitivity and specificity, with a posi-tive correlation to a calibrated reference assay (R² = 0.8461). Dilutional linearity (R2 = 0.9940) and accuracy (98.18%) were confirmed across the analytical titer range of 11-1728 IU/mL. The assay also exhibited high precision, with intra-assay and intermediate preci-sion geometric coefficients of variation of 6.66% and 15.63%, respectively. Robustness testing demonstrated minimal variation across different pseudotyped virus lots, incuba-tion times, and cell counts. Conclusion: The validated NiV-PNA is a reproducible and scalable assay platform for quantifying NiV neutralizing antibodies, offering a safer alternative to virus culture. Its validation and integration into the CEPI Centralized Laboratory Network will enhance global capacity for vaccine evaluation and outbreak preparedness.