Search Results (1,175)

Background: The human leukocyte antigen (HLA) is crucial for antigen presentation and vaccine efficacy. This study examined the association between HLA polymorphisms and the immune response to hepatitis B vaccination in children with acute lymphoblastic leukemia (ALL). Methods: 101 pediatric ALL patients at Shanghai Children's Medical Center affiliated with Shanghai Jiaotong University School of Medicine who tested negative for hepatitis B surface antibody (anti-HBs) and were not infected with hepatitis B received three doses of the hepatitis B vaccine. Anti-HBs titers were measured before and after vaccination. Participants were divided into high- and low-response groups based on post-vaccination anti-HBs titers. Sequence-specific primer polymerase chain reaction (PCR-SSP) was used to genotype HLA-A, -B, -Cw, -DRB1, and -DQB1 alleles. Results: Pre-vaccination anti-HBs titers were 3.38 ± 2.97 mIU/mL, and the post-vaccination seroconversion rate was 100% with mean titers of 429.61 ± 303.13 mIU/mL (p < 0.001). Following immunization, the low-response group (11.88%) had an anti-HBs titer of 56.47 ± 28.38 mIU/mL, while the high-response group (88.12%) had an anti-HBs titer of 479.93 ± 287.70 mIU/mL. There were significant differences in allele frequencies of B*3501 and Cw*0303 between the two response groups (p < 0.05). Binary logistic regression analysis showed that the B*3501 allele was negatively correlated with the anti-HBs response level (p < 0.05). Conclusions: HLA-B*3501 may be associated with lower antibody response levels in children with ALL who completed the full hepatitis B vaccination series. All these children demonstrated protection against the hepatitis B virus (HBV). We will subsequently validate the association between HLA-B*3501 and the level of hepatitis B vaccine immune response in children with ALL through expanding the sample size or conducting a multicenter study. Full article

Monkeypox (Mpox), a zoonotic viral disease caused by the Monkeypox Virus (MPXV), has gained significant attention in recent years due to its increasing incidence and the grave threat it poses to global health. MPXV has spread at a rapid pace during the COVID-19 pandemic, causing 10,000+ confirmed cases and ~300 fatalities in 122 countries. This virus comprises two major clades, Clade I (Central African), which is evidently more virulent, and Clade II (West African), which has caused the recent outbreaks across the world and caused fewer deaths. Clinically, Mpox presents as a milder form with fever, lymphadenopathy, and vesiculopustular rash similar to smallpox. Diagnostic measures such as polymerase chain reaction (PCR) are the main diagnostic confirmatory tools. Advanced diagnostics involve electronic microscopy, serology, and immunohistochemistry. Alternative drugs like tecovirimat and brincidofovir have demonstrated potential for treating smallpox, but there is scanty evidence on their efficacy against MPXV. Most recent advancements in the study of vaccines have resulted in the creation and introduction of MVA-BN (JYNNEOS/Imvanex/Imvamune) and ACAM2000 vaccines, which conferred cross-protection against MPXV. MVA-BN is suggested to perform better than other types due to its enhanced safety and immunogenicity. Researchers are also developing DNA and protein subunit vaccines against Mpox to induce specific immune responses by presenting viral proteins. The discovery of novel vaccine candidates and antiviral treatments will be needed to prevent future outbreaks and reduce the global health burden of Mpox. This review focuses on the characterization of MPXV, summarizing current knowledge on its genomic structure, pathogenesis, replication, potential targets of anti-MPXV drugs, clinical features, and epidemiological patterns, along with recent advances in vaccine development. Full article

Objectives: To analyze the changes in the proportion of the rotavirus vaccine among children born in the 2017–2023 cohort and to assess the current status of rotavirus vaccination coverage in Suzhou, China. To monitor adverse events following immunization (AEFIs) so as to provide data for scientific guidance regarding the rotavirus vaccine. Methods: The basic information of children born between 1 January 2017 and 31 December 2023 in Suzhou and information regarding rotavirus vaccination were collected through the child module of Jiangsu Province Vaccination Integrated Service Management Information System. Information on AEFI case reports was collected from the AEFI monitoring system of the China Information System for Disease Control and Prevention. Descriptive epidemiological methods were used to analyze the rotavirus vaccine characteristics and AEFI classification, and the Mann–Whitney U test was used for comparative analysis. Results: The proportion of children born in the 2017–2023 cohort who received the first dose of the rotavirus vaccine was 14.65%. The reassortant rotavirus vaccine, live, oral, pentavalent (RV5) proportion gradually increased, and the vaccine proportion of children in the 2023 birth cohort reached the highest. The peak age for rotavirus vaccination was between 2 and 8 months. A total of 49,507 children (99.88%) received the first dose of RV5 at the age of 6–12 weeks in this birth cohort, and there was a statistically significant difference in the median duration of the first dose of RV5 among children of different age groups (p < 0.001). A total of 89 cases of AEFIs were reported, and the reported incidence of AEFIs was 3.47/10,000 doses. Among them, 86 cases of general reactions were reported, with a reported incidence of 3.35/10,000 doses, and three cases of abnormal reactions were reported, with a reported incidence of 0.12/10,000 doses. Conclusions: The rotavirus vaccine proportion of children born in Suzhou from 2017 to 2023 was not high. The incidence of AEFI reports from the rotavirus vaccine is relatively low, indicating a favorable safety profile. Efforts should prioritize strengthening health education on rotavirus gastroenteritis to enhance public confidence in vaccination, thereby ensuring the effective prevention and control of rotavirus gastroenteritis. Full article

Background/Objectives: We aimed to determine safe and immunogenic RSVpreF vaccine dose levels for further clinical development in 2–<18 year olds. Methods: The phase 1, age-descending, open-label Picasso trial evaluated different RSVpreF dose levels in respiratory syncytial virus (RSV)-seropositive 2–<5 year olds and 5–<18 year olds who were either healthy or had chronic medical conditions with increased RSV illness risk. Participants received a single dose of RSVpreF (60 µg or 120 µg dose level). The primary objective was to describe safety and tolerability at each dose level and age group, including frequencies of reactogenicity and adverse events (AEs). The secondary objective was to describe RSV neutralizing antibody responses at each dose level and age group 1 month after vaccination. Results: Overall, 127 participants received RSVpreF 60 µg (2–<5 year olds, n = 20; 5–<18 year olds, n = 35) or 120 µg (n = 24 and n = 48, respectively); 54% were male and 69% were White. Local reactions and systemic events were reported in 17–20% and 33–45% of 2–<5 year olds, respectively, and 49–56% and 52–60% of 5–<18 year olds; most were mild or moderate in severity. AEs were reported in 13–15% of 2–<5 year olds and 8–14% of 5–<18 year olds. No AEs leading to withdrawal or vaccine-related serious AEs were reported. RSV-A and RSV-B neutralizing titer geometric mean fold rises from before to 1 month after vaccination with RSVpreF 60 and 120 µg, which were 17.7–20.6 and 42.8–39.8, respectively, in 2–<5 year olds, and 19.0–23.5 and 20.3–20.3, respectively, in 5–<18 year olds. Conclusions: RSVpreF was safe, well tolerated, and elicited immune responses in RSV-seropositive 2–<18-year-old participants, supporting further clinical development in this pediatric population, including those with chronic conditions. Full article

Background: Streptococcus pneumoniae (Spn) is a leading bacterial pathogen responsible for severe invasive diseases, including meningitis, sepsis, and pneumonia. Current pneumococcal vaccines, which are all based on capsular polysaccharide antigens, provide limited protection and are further compromised by post-vaccination serotype replacement. Pneumococcal surface protein A (PspA), a highly conserved virulence factor expressed across diverse serotypes, has emerged as a promising candidate antigen for novel protein-based vaccines. However, progress in this field has been hindered by the absence of standardized in vitro functional antibody assays. Methods: This study established a robust functional antibody detection method for PspA-based protein vaccines by modifying the conventional multiplex opsonophagocytic killing assay (MOPA), originally designed for polysaccharide-based vaccines. Using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) typing, a target strain panel was selected and developed to include representative strains from PspA Family 1-Clade 2 and Family 2-Clades 3 and 4. The MOPA protocol was optimized by extending the phagocytic reaction time to enhance sensitivity. Specificity was confirmed through recombinant PspA competitive inhibition assays. Results: The assay demonstrated high linearity (R² ≥ 0.98) between opsonophagocytic index (OI) and serum dilution, along with acceptable repeatability (CV ≤ 30%) and intermediate precision (CV ≤ 50%). Both preclinical and clinical serum samples exhibited potent bactericidal activity against diverse PspA families, independent of capsule type. Conclusions: This study provided a standardized framework to support the development and regulatory assessment of protein-based pneumococcal vaccines. Full article

Background: Pneumococcal diseases remain a global threat due to the serotype-specific limitations of polysaccharide vaccines. This study evaluated a recombinant protein-based pneumococcal vaccine (PBPV) combining three PspA variants (PRX1/Family1Clade2, P3296/Family2/Clade3, P5668/Family2/Clade4) and detoxified pneumolysin (PlyLD). PspA targets conserved surface epitopes to block immune evasion and achieve broad coverage, while PlyLD neutralizes pore-forming toxins and enhances adaptive immunity. Methods: We evaluated the safety and immunogenicity of the PBPV in animal models. Acute toxicity studies were conducted by administering a single intramuscular injection to ICR mice, whereas chronic toxicity and immunogenicity studies were performed in cynomolgus monkeys via repeated intramuscular injections, with an equal number of male and female animals in both groups. Immune responses were assessed using ELISA, multiplexed opsonophagocytic killing assays (MOPAs), and neutralizing antibody assays. Results: Acute toxicity studies in ICR mice showed no signs of abnormal toxicity or irritation at one-dose levels. In the chronic toxicity study, cynomolgus monkeys received repeated intramuscular injections once every 3 weeks for a total of four administrations, at doses of one dose/monkey and five doses/monkey, followed by a 4-week recovery period. No significant systemic toxic reactions were observed, and the safe dose was determined to be five doses/monkey. In the immunogenicity study of monkey serum, both low-dose and high-dose groups demonstrated significant increases in antigen-specific IgG titers against each component; opsonophagocytic killing activity against pneumococcal strains from Clades 2, 3, and 4 from PspA Families 1 and 2; and neutralization antibody titers against pneumolysin post-vaccination. Conclusions: The recombinant protein-based pneumococcal vaccine exhibited a favorable safety profile and potent immunogenicity in animal models, indicating promise for broad protection against pneumococcal disease. These findings support the further development of PBPVs as a viable alternative to conventional polysaccharide-based vaccines. Full article

Background: Coronavirus disease 2019 (COVID-19) vaccines deliver mRNA packaged in lipid nanoparticles via intramuscular injection. This study investigated several factors influencing antibody production patterns and adverse reactions after vaccination with COVID-19 vaccines. Methods: Among the participants of the Iwaki Health Promotion Project (IHPP), 211 individuals who consented to this study were surveyed regarding antibody titers and adverse reaction symptoms following vaccination. A machine learning approaches such as ridge regression, elastic-net, light gradient boosting, and neural network were applied to extract the variables, and Bayesian network analysis was applied to explore causal relationships between health data and the multi-omics dataset obtained from the IHPP health checkups. Results: Females with lower levels of free testosterone experienced more adverse reactions than males. Moreover, the immune system is more active in younger individuals, causing adverse reactions and higher antibody production. The Spikevax vaccine induced adverse reaction symptoms with higher antibody production in cases of fever. Meanwhile, drinking 2–3 cups of green tea daily seemed to be effective in increasing antibody production. Factors increasing side effect risk include blood natural killer cell count and muscle quality in the vaccinated arm. Plasma metabolome metabolite concentrations, tongue coating bacterial colonization, and folate intake were also identified as factors influencing side effect risk. Furthermore, characteristics of participants at risk for fever symptoms included longer telomere length, higher antibody production patterns, and higher CD4-positive T cell counts. Conclusions: Further investigation of these identified influencing factors is expected to clarify the rationale for new vaccine development and identify lifestyle and dietary habits that enhance vaccine efficacy. Full article

Lipid A is a component of lipopolysaccharide (LPS) of Gram-negative bacteria. Previously, we demonstrated that synthesized lipid A derived from Alcaligenes faecalis (ALA) could enhance antigen-specific immunoglobulin (Ig) A and T helper (Th) 17 responses, when ALA was co-administered experimentally with an antigen as a vaccine adjuvant. This raised concerns about the safety of the ALA usage, since IgA and Th17 responses have been suggested to play a pathogenic role in several immune-mediated diseases, including multiple sclerosis (MS). We investigated whether ALA administrations could exacerbate an animal model of MS, Theiler’s murine encephalomyelitis virus (TMEV) infection. TMEV-infected SJL/J mice were administered ALA at various time points, and their neurological signs were observed for 7 weeks. We found that ALA administrations did not exacerbate TMEV-induced inflammatory disease or viral persistence in the central nervous system (CNS), clinically or histologically. Furthermore, ALA administrations did not enhance TMEV-specific humoral and cellular responses, including IgA and Th17 responses. On the other hand, principal component analysis (PCA) of the fecal, not the ileal, samples showed significant changes in the microbiota, characterized by increases in the relative abundance of bacteria belonging to the phylum Bacteroidota, including the genera Alistipes and Bacteroides. Therefore, ALA injections could be safe for use in immune-mediated diseases, whose immunopathology has been associated with IgA and Th17 responses. Full article

Background/Objectives: Despite high vaccination coverage, influenza remains a public health concern in South Korea, particularly in older adults. Continuous evaluation of vaccine effectiveness (VE) is essential to optimize immunization strategies. Methods: This study evaluated seasonal influenza VE for preventing laboratory-confirmed influenza using a test-negative design through a hospital-based influenza surveillance system in South Korea from 1 November 2024, to 30 April 2025. Demographic and clinical information was collected through questionnaire surveys and electronic medical records. Influenza was diagnosed using rapid antigen tests (RATs) and reverse transcription polymerase chain reaction (RT-qPCR), and vaccine effectiveness was analyzed using multivariable logistic regression. Results: In total, 3954 participants were included, with 1977 influenza-positive cases and 1977 test-negative controls. Influenza A and B accounted for 93.1% and 7.0% of cases, respectively. The adjusted overall VE was 20.4% (95% confidence interval [CI], 8.2–30.9; p = 0.002). VE was higher in adults aged 50–64 years (46.8%) than in those aged ≥65 years (18.8%). VE was 19.9% against influenza A and 45.7% against A/H3N2. VE was higher among individuals tested using RT-qPCR than among those tested using RATs (21.5% vs. 15.7%), and was also greater during the early period than during the late period (20.5% vs. 11.4%). Vaccination did not reduce influenza-associated hospitalization risk (VE, 17.3%; 95% CI, −9.3 to 37.4). A significant reduction in hospitalization risk was observed in adults aged 50–64 years (VE, 46.8%), with no significant benefit in those aged ≥65 years. Conclusions: The 2024–2025 seasonal influenza vaccine provided moderate protection against laboratory-confirmed influenza in adults, with higher effectiveness in those aged 50–64 years. Full article

Background: Adverse Drug Reactions (ADRs) are a significant public concern because of their impact on healthcare systems. Spontaneous reporting of ADRs is crucial for monitoring drug safety and recognizing possible risk factors. The objective of this study was to characterize ADR reports from the Allergy and Clinical Immunology Unit of the G. Martino University Hospital, Messina, Italy. Methods: A retrospective analysis was conducted, including all ADRs spontaneously reported from patients attending the clinic because of at least one previous ADR, from June 2022 to June 2024. Results: A total of 388 reports were collected, mainly from females (71.1%) and adult patients (84.3%). ADRs were mostly immediate, from antibiotics and anti-inflammatory drugs (61.5%), with a high prevalence of cutaneous and respiratory disorders. Delayed reactions were mostly from endocrine therapies, vaccines, and antiepileptics. Anaphylactic shock was present only in 13 ADR reports (3.35%). A higher risk of developing serious ADRs was found in elderly patients aged ≥65 years (p = 0.012). An original finding was that a positive history of allergies (p = 0.023) and past medical history of ADRs (p = 0.045) were negatively correlated to the occurrence of a serious ADR, probably because patients had been previously followed in an allergy setting and alerted about ADRs. Conclusions: This study underlines the role of ADR follow-up in allergy settings to identify preventable traits and related risk factors; appropriate ADR reporting and collaboration between allergists and pharmacovigilance centers can be a winning strategy for ADR prevention. Full article

Background/Objectives: Acute generalized exanthematous pustulosis (AGEP) is a severe drug-induced cutaneous reaction characterized by the abrupt onset of sterile pustules, fever, neutrophilia, and a T cell-mediated type IVd hypersensitivity response. This narrative review synthesizes current evidence on pharmacological triggers, immunopathogenic mechanisms, diagnostic criteria, and differential diagnosis to provide a clinically oriented framework. Methods: A comprehensive literature search was conducted in PubMed/MEDLINE, Scopus, ScienceDirect, and SpringerLink for studies published between 2000 and 2025, complemented by selected clinical reference sources. Studies addressing clinical features, immunological pathways, pharmacovigilance signals, and diagnostic tools for AGEP were included. Synthesis of Evidence: β-lactam antibiotics remain the most frequent triggers, while increasing associations have been reported with hydroxychloroquine, targeted therapies, immune checkpoint inhibitors, psychotropic agents, and vaccines. Immunopathogenesis is driven by IL-36 activation, CXCL8/IL-8–mediated neutrophil recruitment, and IL36RN mutations, explaining overlap with pustular psoriasis. Diagnostic accuracy improves through integration of drug latency, clinical morphology, histopathology, biomarkers, and standardized tools such as the EuroSCAR score. Conclusions: AGEP is a complex pustular reaction induced by diverse drugs and amplified by IL-36-mediated inflammation. Accurate diagnosis requires a multidimensional approach supported by structured algorithms and robust pharmacovigilance to identify evolving drug-associated patterns. Full article

The primary objective of this study was to develop and optimize a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for porcine abortion-associated pestivirus (PAAPeV)—an emerging pathogen that causes severe reproductive disorders in swine, for which no effective treatments or vaccines are currently available. In this study, four sets of LAMP primers were designed and screened for the colorimetric RT-LAMP assay, targeting the highly conserved 5′ untranslated region (5′UTR) of PAAPeV. Three reaction parameters, including reaction temperature, reaction duration, and inner-to-outer primer ratio, were then optimized based on cycle threshold (Ct) values, fluorescence intensity, and color changes of the endpoint products. Subsequently, the specificity and sensitivity of the optimized colordetect RT-LAMP assay were systematically validated, and its diagnostic performance was compared with that of the gold-standard reverse transcription quantitative polymerase chain reaction (RT-qPCR). The results demonstrated that the optimized assay achieved a detection limit of 2 copies/μL under the conditions of 65 °C incubation for 25 min and an inner-to-outer primer ratio of 8:1, with results amenable to naked-eye interpretation. Furthermore, this assay exhibited high specificity, showing no cross-reactivity with other known pestiviruses or prevalent swine pathogens. Clinical sample testing results showed 100% concordance between colordetect RT-LAMP and RT-qPCR. Collectively, this colordetect RT-LAMP assay represents a rapid, sensitive, and specific tool for PAAPeV RNA detection in both clinical laboratories and field settings. Full article

The COVID-19 pandemic has profoundly affected societies around the world. Although the emergency phase of coronavirus disease 2019 (COVID-19) has ended, the threat it poses remains persistent. This review aims to clarify the mechanisms of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection to support effective management of the disease. A central focus is the host cellular response to the viral infection, with particular emphasis on the role of cytokines. Cytokines play a dual role in antiviral defense: they contribute to the inhibition of viral replication and facilitate the clearance of pathogens, yet dysregulated cytokine responses can result in severe immunopathology. Interferons (type I, type II, and type III) and other cytokines are pivotal in activating intracellular antiviral mechanisms and in orchestrating the recruitment of immune cells through extracellular signaling. Effective immune responses to viral infections are governed not only by primary immune cells—such as dendritic cells, T lymphocytes, and B lymphocytes—but also by the local cytokine milieu shaped by infected and neighboring cells. Given the presence of endogenous inhibitors and autoantibodies in vivo, it is essential to evaluate the functional activity of cytokines in clinical samples. We propose a novel approach to quantify biologically active cytokine levels. Full article

The Coronavirus Disease 2019 (COVID-19) pandemic and its prolonged effects have been widely discussed on social media, and these discussions have been analyzed in various studies. A long-term analysis of Twitter (now “X”) posts regarding COVID-19 vaccination is essential for informing policy and improving public health communication strategies. In addition, to prevent the spread of infectious diseases, it is crucial to rapidly promote vaccination while mitigating the impact of negative sentiment toward vaccination on social media platforms. Therefore, identifying the key factors behind negative discussions is important for guiding policy decisions and shaping responses. In this study, we collected Japanese tweets (posts) containing the words “Corona” and “vaccine” that were posted from February 2021 to December 2022. The results indicate that negative sentiment was primarily driven by concerns about adverse reactions and general fear and anxiety, which were particularly prominent before vaccination for the general public began, as well as mentions of pain during and after vaccination. While concerns about adverse reactions persisted throughout the analysis period, their prominence decreased over time as positive reactions became more frequent. Our findings provide insights into the characteristics and key factors behind negative discussions on COVID-19 vaccination in the Japanese context and may help improve public health communication strategies. Full article

Background: Children and adolescents are pivotal in the transmission of influenza, and vaccination remains the most effective preventive measure. Cell-based influenza vaccines offer advantages over traditional egg-based vaccines by reducing egg-adapted mutations and improving antigenic match. SKYCellflu^® quadrivalent influenza vaccine (QIV; SK bioscience, Korea), the first cell-based QIV licensed in Korea for individuals aged 6 months and older, offers potential advantages; however, its real-world effectiveness in the Korean pediatric population remains limited. Objective: This study aimed to estimate the real-world effectiveness of SKYCellflu^® QIV, a cell-based QIV, in preventing laboratory-confirmed influenza among children and adolescents aged 6 months to 18 years in Korea during the 2024–2025 influenza season. Methods: A multicenter, prospective, test-negative case–control study was conducted from October 2024 to May 2025 across 25 institutions in Korea. Children and adolescents aged 6 months to 18 years who presented within 7 days of the onset of influenza-like illness (fever ≥ 38 °C and at least one respiratory symptom) were enrolled. Influenza infection was confirmed using rapid antigen tests or polymerase chain reaction; participants who tested positive were classified as cases, and those who tested negative for influenza served as controls. All participants were further categorized as vaccinated or unvaccinated based on receipt of SKYCellflu^® QIV. Those who received other influenza vaccines during the season were excluded. Vaccination status was verified through medical records and the national immunization registry. Results: A total of 1476 participants were included (751 cases, 725 controls). The overall adjusted vaccine effectiveness (aVE) was 45.57% (95% CI, 29.38–58.04). The vaccine demonstrated the highest effectiveness in children aged 6–35 months (aVE: 88.55%; 95% CI, 60.39–96.11). Effectiveness was higher against influenza B (aVE: 61.28%; 95% CI, 35.76–76.30) than influenza A (aVE: 41.63%; 95% CI, 22.55–56.01). The vaccine’s effectiveness in adolescents was not statistically significant due to the small sample size in this age group. Conclusions: This multicenter test-negative study provides the first real-world effectiveness of SKYCellflu^® QIV in a Korean pediatric population. The results suggest substantial protection in younger children, particularly against influenza B, and support the continued use of annual influenza vaccination in this population. Further studies with larger adolescent cohorts are needed to confirm these findings in older age groups. Full article