Search Results (1,617)

In southern Brazil, dengue transmission in the state of Paraná has shown a significant increase in the number of cases since the first recorded occurrence in 1995, with more frequent outbreaks in the west, northwest, and north of the state. We evaluated the impact of a campaign of dengue vaccination administered to a fraction of the population in 30 municipalities in the state by conducting a 15-year interrupted time-series ecological study using data obtained from an official Brazilian data register. We modeled dengue incidence using Poisson regression adjusted by covariates (demographic, climate, and epidemiological factors), allowing for specific temporal variation for each site. A reduction of 18.7% in dengue incidence rate was estimated for a vaccination coverage of 100%. Although there was an increase in the crude dengue incidence rate, considering the three-dose coverage achieved in the municipalities, we estimated an 8.2% relative reduction in the incidence rate. This reduction would increase to 17% with a hypothetical coverage of 90%. The campaign was more effective in small municipalities since they had higher vaccination coverage. These findings underscore the significant impact of the vaccination campaign on reducing dengue incidence trends across the targeted municipalities. Full article

Background: Whooping cough caused by Bordetella pertussis is re-emerging despite high vaccination coverage, with rising incidence in adolescents and adults in the acellular vaccine (aP) era. This narrative review synthesizes evidence on the drivers of this paradox and their implications for pertussis control. Methods: We conducted a structured (but not fully systematic) literature search and narrative synthesis of PubMed, Web of Science, and Embase for publications from January 2000 to February 2025 using terms related to “Bordetella pertussis,” “pertussis resurgence,” “acellular vaccine,” “waning immunity,” “ptxP3,” “pertactin-deficient,” “macrolide resistance,” and “whole-genome sequencing.” English-language, peer-reviewed studies, surveillance reports, genomic analyses, and immunological investigations were included. About 1900 records met broad eligibility criteria and were screened, and key studies were selected for narrative synthesis. Results: The resurgence appears to result from three convergent factors: (1) waning and non-sterilizing aP-induced immunity, which allows bacterial colonization and transmission; (2) vaccine-driven genomic evolution of B. pertussis, marked by global dominance of the ptxP3 lineage and widespread pertactin-deficient (PRN−) strains; and (3) emergence of macrolide-resistant clones, exemplified by the MT28-Shanghai strain. Whole-genome sequencing (WGS) has been central for defining these processes and clonal sweeps under combined vaccine and antibiotic pressure, supporting a three-driver framework of waning aP immunity, vaccine-driven evolution, and macrolide resistance. Conclusions: Pertussis resurgence illustrates pathogen adaptation to human interventions. Effective mitigation requires WGS-integrated global surveillance, re-evaluation of vaccine formulations to keep pace with antigenic change, and strengthened antibiotic stewardship, alongside development of next-generation vaccines that induce durable mucosal immunity and block transmission. Full article

Introduction: Seroprevalence of antibodies for vaccine-preventable diseases (VPDs), due to vaccination or previous infection, can provide a more accurate estimate of immunity compared to vaccination coverage data alone. This study aimed to examine the seroepidemiology and spatial distribution of VPD seroprevalence in Samoa in 2018 and 2019. Methods: Dried blood spot (DBS) samples were collected from two nationally representative community-based surveys of participants aged ≥5 years from the Surveillance and Monitoring to Eliminate Lymphatic Filariasis and Scabies from Samoa (SaMELFS) project. DBSs were tested using multiplex bead assays (MBAs) to detect antibodies against measles, rubella, diphtheria, and tetanus. Seroprevalence was estimated at the national and primary sampling unit (PSU) levels, and cluster analysis was completed using SaTScan. Results: Overall, 8394 valid MBA results were analysed across 35 PSUs. The highest overall seroprevalence was observed for tetanus (91.0%; 95% CI: 90.2–91.7), followed by diphtheria (83.7%; 95% CI: 82.7–84.7), rubella (79.3%; 95% CI: 78.2–80.3), and measles (45.8%; 95% CI: 44.8–46.9) with substantial heterogeneity across PSUs. Clusters of seronegativity to measles (relative risk [RR]: 1.16, p < 0.001) and diphtheria (RR: 1.16, p < 0.001) were also identified. Conclusions: These findings demonstrate significant variation in seroprevalence and pockets of low population immunity to multiple VPDs, highlighting the key advantage of an integrated rather than siloed approach. The relatively high seroprevalence to rubella suggests potential community transmission, emphasising the need to strengthen congenital rubella surveillance and improve vaccination coverage. Identifying low immunity to VPDs can provide an early warning to potential outbreak risk and support the Ministry of Health to target public health interventions in higher-risk areas. Full article

Intravesical Bacillus Calmette–Guérin (iBCG) immunotherapy is the standard adjuvant treatment of non-muscle-invasive bladder cancer (NMIBC). Among the potential complications, cases of mycotic aneurysms and acute respiratory distress syndrome (ARDS) are rare but can be life-threatening. Because prior reports have not included whole-genome sequencing (WGS) of clinical Mycobacterium bovis BCG (M. bovis BCG) isolates to assess whether the infecting strain acquires mutations in vivo, we performed WGS in a severe disseminated iBCG-related infection. A 72-year-old man with bladder cancer underwent iBCG instillation. Twelve months after the final instillation, the patient developed an abdominal aortic aneurysm, which was detected and treated with endovascular aneurysm repair (EVAR). Two months later, the patient presented with fever, abdominal pain, and septic shock. Contrast-enhanced computed tomography (CT) and ¹⁸F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) showed rapid aneurysm enlargement. Ziehl–Neelsen staining and PCR of aortic material identified M. bovis BCG. Direct PCR on BAL fluid and urine was negative; however, BAL and urine culture subsequently grew M. bovis BCG, and PCR performed on the culture isolate confirmed M. bovis BCG. Despite combined antituberculosis triplet therapy (isoniazid, rifampicin, and ethambutol), the patient developed ARDS, which gradually improved after surgical management. WGS (with >96% genome coverage) showed the isolate was highly concordant with the vaccine strain and lacked additional virulence-associated mutations, including in esxM. This case illustrates that severe systemic iBCG-related complications can occur without detectable in vivo acquisition of virulence-enhancing mutations; however, interpretation is limited by the single-case design and the absence of host genetic susceptibility testing. Our findings underscore the need for prolonged vigilance regarding late-onset vascular and pulmonary complications after iBCG, and highlight the importance of early multidisciplinary management. Full article

Background/Objective: Despite available SARS-CoV-2 vaccines, coverage gaps persist due to unequal distribution and limited access. Microarray patches offer a promising solution to address these challenges, providing a safer and easier-to-use alternative. We present a randomised, double-blind Phase I clinical trial evaluating the SARS-CoV-2 spike protein subunit vaccine, HexaPro, delivered via a high-density microarray patch (HD-MAP). Methods: Forty-four healthy adults aged 18–50 years were assigned to receive either 0 µg, 15 µg, or 45 µg of HexaPro via the HD-MAP, with the primary objective of assessing safety and tolerability. Results: The HD-MAP HexaPro vaccine was found to be safe and well tolerated, with only mild adverse events reported. Following vaccination significant increases in spike-specific IgG titers were observed by 7 days and remained stable through day 90. This IgG response effectively neutralised multiple SARS-CoV-2 variants. Additionally, the HexaPro HD-MAP was stable for up to 12 months at 40 °C. Conclusions: These findings support the continued clinical development of HD-MAPs as an alternative vaccination strategy. Full article

Dengue is a mosquito-borne viral disease transmitted by Aedes aegypti, the main vector in the Americas. The lack of effective antiviral treatments, limited vaccine coverage, and the increasing resistance of mosquitoes to conventional insecticides emphasize the need for alternative vector control strategies. Plant-derived larvicides represent a promising and eco-friendly approach. This study characterized the phytochemical profile of Persea americana Mill. (var. Lorena) and evaluated its larvicidal activity against Ae. aegypti (Rockefeller strain). The phytochemical profile was assessed through qualitative screening, UV-Vis spectrophotometry, and UHPLC analysis. Larvicidal activity was evaluated against third-instar larvae of Ae. aegypti (Rockefeller strain) and the median lethal concentration (LC₅₀) values were determined. Preliminary screening of ethanolic extracts revealed the presence of various secondary metabolites of pharmacological relevance, including alkaloids, coumarins, tannins, flavonoids, saponins, triterpenes/sterols, and quinones. UV-Vis spectra displayed distinct absorption patterns, with a prominent peak near 260 nm, consistent with the presence of aromatic compounds. UHPLC profiling revealed high chemical diversity across different plant parts, with 70, 98, 71, and 52 peaks (above 1 × 10⁵ intensity) detected in seed, flower, pulp, and leaf extracts, respectively. Larvicidal bioassays showed significant activity, particularly in the seed extract, with LC₅₀ values (µg/mL) of 3.8 (3.3–4.1) for seeds, 22.4 (21.8–23.9) for flowers, 23.0 (21.5–24.6) for pulp, and 29.7 (28.1–31.2) for leaves. This study highlights the larvicidal potential of ethanolic extracts from P. americana (var. Lorena), with the seed extract exhibiting the highest chemical diversity and bioactivity against Ae. aegypti larvae. The detection of key secondary metabolites, including flavonoids, alkaloids, and saponins, supports the development of an effective, plant-based larvicide for sustainable vector control strategies. Full article

Vaccination is the primary method of preventing influenza. During the 2023–24 season, the influenza vaccination for all children between 6 and 59 months was introduced for the first time in Spain. To assess the coverage and adherence of influenza vaccination in childhood during the first two seasons of a vaccination program, as well as to identify the factors associated with influenza vaccination in all children under 5 years of age and those from 5 to 14 years of age with risk factors. Retrospective observational study. All children eligible for the flu vaccine in Central Catalonia during the 2023–24 and 2024–25 seasons were included. A total of 39,937 children were studied. Of these, 79.1% had not been vaccinated for influenza in either of the seasons studied. Influenza vaccination coverage in childhood was 18.1% and 19.3% in the 2023–24 and 2024–25 seasons, respectively. In the 6- to 59-month age range, coverage was 19.1% and 28.9% in the 2023–24 and 2024–25 seasons, respectively. The adherence to vaccination in both seasons was 17%. Some variables (being a non-native person, living in an urban area, having more than one risk factor, or certain underlying conditions) were associated with the influenza vaccination. Coverage and adherence to influenza vaccination in childhood are very low, despite the implementation of a routine influenza vaccination program. Full article

Objectives: Despite high overall vaccination coverage in Galicia, Spain, human papillomavirus (HPV) vaccine uptake remains below the 90% target set by the World Health Organization for 2030. This study aimed to assess baseline knowledge of HPV and attitudes towards HPV vaccination among Galician adolescents and to evaluate the impact of a brief educational intervention delivered as a “pill of knowledge”. Methods: A quasi-experimental pre-/post-intervention study was conducted among 967 students aged 12–16 years from 16 secondary schools in Galicia during the 2023–2024 academic year. A concise, structured 15-min educational session termed a “pill of knowledge” was delivered, and HPV-related knowledge and vaccination intention were measured immediately before and after the intervention using a standardized questionnaire. Results: Following the “pill of knowledge”, the mean proportion of correct responses increased by 30.1 ± 16.6% across all knowledge items. Among unvaccinated participants, intention to accept HPV vaccination rose from 77.7% to 94.4% in girls and from 64.7% to 85.8% in boys. Pre-intervention predictors of vaccination intention included perceived vaccine efficacy and baseline HPV knowledge. Post-intervention independent predictors comprised being female, younger age (12–13 years), and prior sexual education delivered by teachers or parents. The overall predictive accuracy of the logistic regression model for vaccination intention improved from 75.6% before the intervention to 92.7% afterwards. Conclusions: A brief, school-based “pill of knowledge” produced substantial and immediate improvements in HPV knowledge and vaccination acceptance among Galician adolescents. These findings strongly support the systematic incorporation of short, evidence-based educational interventions of this kind into the school setting as an effective public health measure to increase HPV vaccine coverage and advance progress toward WHO elimination targets. Full article

Objective: To explore the problems with non-National Immunization Program vaccinations in Hubei Province and to provide the basis for follow-up vaccination and management. Methods: Vaccination data on non-NIP/NIP vaccine doses were extracted from the Hubei Provincial Immunization Planning Information Management System. Descriptive epidemiological analyses were conducted to examine dose administration, vaccine-type composition, regional distribution, and substitution patterns. The trend χ² test was used to assess temporal significance. Multistage regression analysis was performed using Joinpoint software. Results: From 2011 to 2024, a total of 91,009,259 doses (annual average: 6,500,661) with 35 types of non-NIP vaccines were administered in Hubei Province, China. The top five vaccines by doses administered were influenza vaccine, rabies vaccine, Hemophilus influenzae type b conjugate vaccine, varicella attenuated live vaccine, and enterovirus 71 inactivated vaccine. Before 2024 (2011–2023), vaccine utilization showed a long-term upward trend: per 10,000, population usage rose from 657.07 (2011) to a peak of 2393.21 (2023) (Increase: 264.22%, χ² = 138.62, p < 0.05) (AAPC = 10.92%, p < 0.05) and non-NIP’s share of total vaccines increased from 25.52% (2011) to 65.95% (2023), (Increase: 154.33%, χ² = 89.47, p < 0.05) (AAPC = 8.74%, p < 0.05). A notable reversal occurred in 2024. Non-NIP doses dropped from 13,971,544 (2023) to 10,238,861 (2024) with population usage falling from 2393.21 (2023) to 1755.03 (2024) (decrease: 26.66%) per 10,000, with the top three declines being in inactivated polio vaccine (IPV) (decrease: 49.53%), influenza vaccine (decrease: 44.21%), and oral rotavirus attenuated live vaccine (decrease: 43.50%). The total number of substitutive non-National Immunization Program (non-NIP) vaccine doses administered reached 16,618,755, with an overall substitution rate of 10.10%. This rate showed a steady upward trend from 5.57% in 2011 to 24.74% in 2023 (trend χ² = 15.11, p < 0.05), yet it increased to 28.03% in 2024. Conclusions: Non-NIP vaccines and NIP-substitute use grew steadily for over a decade, then contracted sharply in 2024. Decision-makers should investigate the sudden dip, differentiate discretionary from replacement demand, and reallocate funds to sustain equity and prevent further erosion of coverage. Full article

Background: Chromobacterium violaceum is an emerging multidrug-resistant (MDR) Gram-negative bacterium associated with severe septicemia, abscess formation, and high mortality, particularly in immunocompromised individuals. Increasing antimicrobial resistance and the absence of approved vaccines underscore the urgent need for alternative preventive strategies. Traditional vaccine approaches are often inadequate against genetically diverse MDR pathogens, prompting the use of computational immunology and reverse vaccinology for vaccine design. Objectives: This study aimed to design and characterize a novel multi-epitope subunit vaccine (MEV) candidate against C. violaceum using a comprehensive pangenome-guided subtractive proteomics and immunoinformatics pipeline to identify conserved antigenic targets capable of eliciting strong immune responses. Methods: Comparative genomic analysis across eight C. violaceum strains identified 3144 core genes. Subtractive proteomics filtering yielded two essential, non-homologous, surface-accessible, and antigenic proteins—penicillin-binding protein 1A (Pbp1A) and organic solvent tolerance protein (LptD)—as vaccine targets. Cytotoxic T-lymphocyte (CTL), helper T-lymphocyte (HTL), and B-cell epitopes were predicted and integrated into a 272-amino-acid MEV construct adjuvanted with human β-defensin-4A using optimal linkers. The construct was evaluated through structural modeling, molecular docking with TLR4, molecular dynamics simulation, immune simulation, and in silico cloning into the pET-28a(+) vector. Results: The MEV construct exhibited strong antigenicity, non-allergenicity, and non-toxicity, with stable tertiary structure and favorable physicochemical properties. Docking and dynamics simulations demonstrated high binding affinity and stability with TLR4 (ΔG = −16.2 kcal/mol), while immune simulations predicted durable humoral and cellular immune responses with broad population coverage (≈89%). Codon optimization confirmed high expression potential in E. coli K12. Conclusions: The pangenome-guided immunoinformatics approach enabled the identification of conserved antigenic proteins and rational design of a promising multi-epitope vaccine candidate against MDR C. violaceum. The construct exhibits favorable immunogenic and structural features, supporting its potential for experimental validation and future development as a preventive immunotherapeutic against emerging MDR pathogens. Full article

Background: Promoting seasonal influenza vaccination among parents may help increase the coverage of seasonal influenza vaccination among both parents and children. This study aims to investigate determinants of behavioral intention to receive a seasonal influenza vaccination among parents of children aged 0–15 years to protect themselves. Methods: A cross-sectional survey was conducted among parents of children aged 0 to 15 years with administrative health records in Shenzhen, China, between September and October 2024. Participants were recruited through multistage random sampling. First, 10 community health centers were randomly selected in Shenzhen. Within each selected center, 200 parents were randomly selected. Multivariate logistic regression models were fitted. Results: Among 1504 parents, 47.6% intended to receive a seasonal influenza vaccination in the next year. After adjusting for significant background characteristics, parents’ intention to receive a seasonal influenza vaccination was associated with a higher intention to vaccinate their children against seasonal influenza (AOR: 20.39). At the individual level, eight items measuring illness representations of seasonal influenza were associated with higher odds of intending to receive such a vaccine (AOR: 1.15–1.25), including identity (identifying symptoms), timeline, negative consequences, personal and treatment control, concern, negative emotions, and coherence. At the interpersonal level, parents who had higher levels of general and family-oriented altruism (AOR: 1.10–2.47), better family harmony (AOR: 1.07), higher exposure to information related to seasonal influenza on social media (AOR: 1.24–1.38), and thoughtful consideration of information veracity (AOR: 1.33) were more likely to report an intention. Conclusions: There are strong needs to promote seasonal influenza vaccination among parents in China. Full article

Background: Children with congenital heart disease (CHD) are at substantially increased risk for respiratory infections, which occur more frequently and with greater severity than in healthy peers. This heightened vulnerability stems from multifactorial immune impairment, including defects in innate and adaptive immunity, chronic inflammation related to abnormal hemodynamics and hypoxia, reduced thymic function, and genetic syndromes affecting both cardiac and immune development. Viral pathogens—particularly respiratory syncytial virus (RSV), influenza viruses, and SARS-CoV-2—account for most infections, although bacterial pathogens remain relevant, especially in postoperative settings. Methods: This narrative review summarizes current evidence on infection susceptibility in children with CHD, the epidemiology and clinical relevance of major respiratory pathogens, and the effectiveness of available preventive measures. Literature evaluating immunological mechanisms, infection burden, vaccine effectiveness, and passive immunization strategies was examined, along with existing national and international immunization guidelines. Results: Children with CHD consistently exhibit higher rates of hospitalization, intensive care unit admission, mechanical ventilation, and mortality following respiratory infections. RSV, influenza, and SARS-CoV-2 infections are particularly severe in this population, while bacterial infections, though less common, contribute substantially to postoperative morbidity. Preventive options—including routine childhood vaccines, pneumococcal and Haemophilus influenzae type b vaccines, influenza vaccines, COVID-19 mRNA vaccines, and RSV monoclonal antibodies—demonstrate strong protective effects. New long-acting RSV monoclonal antibodies and maternal vaccination markedly enhance prevention in early infancy. However, vaccine coverage remains insufficient due to parental hesitancy, provider uncertainty, delayed immunization, and limited CHD-specific evidence. Conclusions: Respiratory infections pose a significant and preventable health burden in children with CHD. Enhancing the use of both active and passive immunization is essential to reduce morbidity and mortality. Strengthening evidence-based guidelines, improving coordination between specialists and primary care providers, integrating immunization checks into routine CHD management, and providing clear, condition-specific counseling to families can substantially improve vaccine uptake and clinical outcomes in this vulnerable population. Full article

Introduction: Children with chronic kidney disease (CKD) are susceptible to infections due to impaired immunity, immunosuppressive treatments, and dialysis, which lead to increased mortality, morbidity, and hospitalization rates. Immunization is an efficient preventive strategy, but despite the long-existing guidelines, vaccination rates of children with CKD remain suboptimal. Aim: This review aims to summarize the available data on vaccine-preventable infection morbidity and vaccination coverage in children with CKD, the reasons of vulnerability and suboptimal vaccination of this population and strategies that have been proposed for their overcoming. Results: Vaccination coverage studies for children with CKD are limited and outdated but, despite their variability, they confirm suboptimal vaccine coverage. The vulnerability of children with CKD to infectious dis-eases has been better understood with advanced molecular studies of their immune re-sponse. Several barriers, some of them unique to this population, hamper adherence with vaccination guidelines. Targeted interventions at different levels that have already been tried in adults with CKD, such as enhanced communication with families, cocooning strategies for the most vulnerable, education of specialists on vaccines, and organization of vaccination teams, seem promising in improving vaccination rates and infection prevention. Conclusions: The suboptimal protection from infections of children with CKD can be improved with prioritization of vaccination in their complicated care. Full article

Background: Severe pediatric influenza remains a major clinical burden, yet its phenotype in the post-COVID-19 period has not been fully characterized. The pandemic’s infection-control measures created an “immunity gap” among children, altering viral epidemiology and severity. This multicenter study from Türkiye defines the clinical spectrum and outcomes of influenza cases requiring intensive care, providing one of the first regional datasets after the pandemic. Methods: We retrospectively analyzed 85 children with influenza admitted to five tertiary PICUs in İstanbul between 2024 and 2025. Demographics, clinical features and outcomes were compared across groups. Predictors of sepsis, pediatric ARDS, and mechanical ventilation were identified through multivariate logistic regression. Results: Influenza A + RSV co-infection occurred in 14% and affected significantly younger infants, presenting with more severe respiratory distress, hypoxemia, and bronchiolitis. Influenza B was associated with distinct neurotropic features—encephalopathy and seizures in 48%—and a higher risk of sepsis (OR 3.27, 95% CI 1.02–10.53). Hypoxemia, elevated vasoactive–inotropic score, and high PaCO₂ independently predicted mechanical ventilation and poor outcomes. Only 2–4% of children had received influenza vaccination. Conclusions: This multicenter analysis reveals a post-pandemic surge of severe pediatric influenza characterized by dual respiratory and neurological phenotypes. RSV co-infection drives early respiratory failure in infants, whereas Influenza B carries a disproportionate risk of neuroinflammation and sepsis. The study provides evidence from Türkiye that the post-COVID “immunity gap” and critically low vaccination coverage contribute to increased PICU admissions. Strengthening pediatric influenza immunization and RSV prevention policies is urgently warranted to mitigate these outcomes. Full article

Background/Objectives: American Indian/Alaska Native individuals exhibit a higher prevalence of carriage of Streptococcus pneumoniae and are at increased risk of invasive pneumococcal disease compared with the general US population, driven by persistent inequities in health determinants. Although the use of pneumococcal vaccines has reduced carriage of vaccine serotypes, the prevalence of carriage of non-vaccine serotypes has increased. Methods: This study was a descriptive subgroup analysis of the PNEU-DAY study (NCT03547167; EudraCT 2017-004915-38). Safety, tolerability, and immunogenicity of sequential administration of either V114, a 15-valent pneumococcal conjugate vaccine (PCV), or 13-valent PCV (PCV13), followed 6 months later by 23-valent pneumococcal polysaccharide vaccine (PPSV23), were evaluated in pneumococcal vaccine-naïve American Indian adults with or without pre-defined risk factors for pneumococcal disease. Polymerase chain reaction testing assessed nasopharyngeal/oropharyngeal carriage of S. pneumoniae. Results: Following administration of PCV and PPSV23, the proportions of participants with adverse events were generally comparable between vaccination groups. V114 and PCV13 were immunogenic for all respective vaccine serotypes, with V114 inducing robust immune responses to the two additional serotypes not included in PCV13 (22F and 33F), based on opsonophagocytic activity geometric mean titers and immunoglobulin G geometric mean concentrations at 30 days post-vaccination. Sequential administration with PPSV23 was immunogenic in both vaccination groups. Nasopharyngeal/oropharyngeal carriage of S. pneumoniae was observed in 16.7% to 22.6% of American Indian participants across the study timepoints. Conclusions: V114 was well tolerated and immunogenic for the 15 serotypes in V114 when administered either alone or followed by PPSV23. Use of V114 has the potential to expand serotype coverage and protect against pneumococcal disease resulting from serotypes absent in PCV13 among American Indian adults. Full article