Search Results (339)

Introduction: Inequities in access to medicines persist for asylum seekers, refugees, and undocumented migrants in Europe. For vaccines, access gaps not only exist for these groups in childhood routine immunization, but also for life-course and catch-up vaccinations. As part of a broader project examining access to medicines and vaccines for migrants across all stages of the migration cycle, this scoping review synthesizes evidence on the determinants of access to vaccines. Methods: We conducted a scoping review across PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Database of Systematic Reviews, Scopus, and grey literature sources, covering the period 2000–2024. Sources were eligible if they addressed access to vaccines among migrants. We examined access to vaccines along the life course, and across phases of the migratory cycle, including departure, transit, reception and settlement, and return or deportation. Results: A total of 47 research studies and grey literature reports were included. Most studies focused on migrants in reception and settlement (destination) settings, with only twelve sources addressing other phases of the migratory cycle. Across European countries, migrants were frequently reported to have lower uptake of routine vaccines (e.g., measles–mumps–rubella (MMR), polio, diphtheria–tetanus–pertussis (DTP), and human papillomavirus (HPV)) and COVID-19 vaccines than host populations. The most frequently reported barriers were related to migrants’ legal status, administrative requirements, and lack of documentation, alongside poor affordability of vaccination, limited awareness of their rights, and mistrust in the health system. Conclusions: Health systems need to adopt innovative approaches to expand vaccine access for migrant populations. Further, protecting confidentiality is essential for building trust and reducing ethical and legal risks. Flexible and coordinated vaccination strategies are required to address migrants’ mobility across the different migration stages and settings. Our findings appeal for sustained improvements in access to vaccines among migrants in Europe, contingent on strong policy commitments to equity, data protection, and the adoption of life-course and catch-up vaccination strategies. Full article

Background: The 2025 EPI Managers’ Meeting for West African countries in Guinea was a critical platform for EPI managers to make an in-depth analysis of immunization programmes. We present a structured analysis of immunization status in West Africa using a WHO Health System model to move beyond descriptive reporting toward systemic analysis for actionable solutions. Methods: The meeting convened EPI managers from 14 of the 17 West African countries and partners supporting the immunization program. Country and regional presentations, immunization and surveillance data and meeting discussions were analysed through a framework identifying (1) core problems, (2) systemic barriers using WHO health systems building blocks and (3) actionable recommendations or call for action. Results: Analysis revealed stagnating immunization coverage. Recovery from COVID-19 pandemic disruptions remained limited, with persistent outbreaks of vaccine-preventable diseases (VPD). Among the five Immunization Agenda 2030 objectives assessed, only Maternal and Neonatal Tetanus (MNT) elimination was on track. Four critical challenges emerged: (1) Routine immunization stagnation with DTP3 median coverage of 76%. This was associated with challenges related to poor data quality, weak implementation of innovative vaccination strategies and donor dependency, as 88.2% of countries financed less than 50% of routine vaccine costs domestically. (2) Sub-optimal progress in Big Catch-Up (BCU) implementation in some countries, revealing poor health system resilience. (3) Inability to sustain high coverage for new vaccine introductions despite significant progress, highlighting demand and service delivery gaps. (4) Persistent VPD outbreaks with geographical expansion and the resurgence of diphtheria epidemics since 2023. Conclusions: Persistent immunization challenges in West Africa appear to reflect interconnected systemic challenges, suggesting the need for a fundamental shift toward subnational strategies, integration of immunization services within primary health care (PHC) and improved data quality. Sustainable financing of the national EPI and acceleration of local vaccine manufacturing is essential to achieve immunization sovereignty in West Africa. Country Call for Action provides strategic guidance to reverse the trend toward the Immunization Agenda 2030 targets. Full article

Background/Objectives: Pertussis, caused by Bordetella pertussis, remains a global health problem, despite high vaccine coverage. In countries with high acellular pertussis vaccine (aPV) coverage, pertactin-negative B. pertussis strains emerged due to vaccine pressure on the sole bactericidal target of aPVs. In contrast, the live attenuated intranasal vaccine BPZE1 induces bactericidal antibodies to multiple antigenic targets that kill pertactin-positive and pertactin-negative B. pertussis strains. Here, we developed two high-throughput human complement-mediated serum bactericidal assays (SBA) using clinical samples to demonstrate bactericidal activity against B. pertussis. Methods: Assay accuracy, precision, linearity, range and robustness of the SBAs against pertactin-positive and pertactin-negative B. pertussis strain B1917 were determined using a panel of commercial and clinical trial samples. The assay was used to analyze a cohort of BPZE1 and tetanus–diphtheria–acellular pertussis (Tdap) vaccinee samples at baseline and 28 days post-vaccination from a phase 2b clinical trial. Results: Inter- and intra-assay variability of both assays had coefficients of variation for repeatability < 20% and for intermediate precision of <30%. The assays measured titers ranging from ~8 to ~20,000 and showed high linearity (R² > 0.98) between bactericidal titers and serum dilutions. On clinical samples, BPZE1 induced similar bactericidal activity as Tdap against pertactin-positive B. pertussis, despite inducing lower anti-aP antigen IgG concentrations than Tdap. Additionally, BPZE1 induced serum bactericidal activity against pertactin-negative B. pertussis, while Tdap did not. Conclusions: High-throughput SBAs were developed and qualified against pertactin-positive and pertactin-negative B. pertussis, enabling measurement of 120 samples per day per analyst. These assays will support clinical development of next-generation pertussis vaccines, including BPZE1. Full article

Background: In Uganda, COVID-19-related disruptions increased the number of children who missed scheduled routine vaccination (defaulters). Identifying and following up with defaulter children is important for improving vaccination coverage. This paper describes Uganda’s experience in revitalizing community-led defaulter tracking to improve vaccination coverage post-COVID-19 in four purposefully selected districts. Methods: During two 6-month periods in 2022 and 2024, healthcare workers (HCWs) worked with village health teams (VHTs) to review health facility-based immunization registers, identify and track defaulters aged 0 to 59 months. VHTs visited identified defaulters’ homes, reviewed vaccination histories and reminded caregivers to bring defaulters to immunization sites for catch-up vaccination. Results: Overall, 20,922 defaulters were identified by health register review; VHTs located 15,749 (75.3%) through household visits, of whom 3688 (23.4%) were verified as previously vaccinated based on their home-based vaccination records, leaving 12,061 as true defaulters. Among the true defaulters, 9662 (80.1%) received at least one catch-up vaccination after follow-up by the VHT. The most frequently administered catch-up vaccines were measles–rubella first dose (MR1) at 55.4%, followed by diphtheria–tetanus–pertussis third dose (DTP3) at 48.3% and Bacillus Calmette–Guérin (BCG) at 47.4%. Among the 2399 children who remained unvaccinated after follow-up, the most common reasons were relocation outside the original catchment area (49.5%) and caregiver intention to vaccinate later (16.3%). Conclusion: Community-led defaulter tracking was feasible and improved vaccination uptake in post-COVID-19 Uganda. Strengthening the quality and availability of health facility immunization data, along with targeted community engagement, caregiver reminders and integrated vaccination services would improve identification and follow-up of defaulters, reducing population immunity gaps. Full article

Background: Vaccination coverage declined in many countries during the COVID-19 pandemic, including in Bosnia and Herzegovina. We evaluated a telephone-based outreach intervention implemented in primary healthcare facilities (PHCs) in the Federation of Bosnia and Herzegovina. The intervention targeted missed routine vaccinations among children aged 0–7 years. Method: Using a programmatic, non-randomized pre–post design, healthcare teams reviewed registries to identify under-vaccinated children, and parents were contacted by phone to facilitate catch-up visits. Results: Among age-eligible children, vaccination coverage increased from 66.5% to 74.2% for measles–mumps–rubella (MMR) dose 1, from 43.4% to 51.7% for MMR dose 2, and from 50.4% to 55.9% for the fourth dose of diphtheria–tetanus–acellular pertussis-inactivated poliovirus–Haemophilus influenzae type b vaccine (DTaP-IPV-Hib). Mixed-effects models adjusting for age, sex, and clustering by facility and canton showed higher odds of vaccination post-intervention for MMR dose 1 (adjusted odds ratio [aOR] 1.65), MMR dose 2 (aOR 1.61), and DTaP-IPV-Hib dose 4 (aOR 1.39; all p < 0.001). Conclusions: These results show that registry-based, proactive outreach can yield significant improvements in routine childhood vaccination coverage in real-world settings and may be a scalable approach for decentralized health systems recovering from pandemic disruptions. Full article

Blastic plasmocytoid dendritic cell neoplasm (BPDCN) is a rare myeloid malignancy, characterized by the involvement of multiple organs, including the skin, bone marrow and blood, lymph nodes and the central nervous system. According to tumor location, the disease is classified as skin-only, systemic-only, and skin and systemic. The cutaneous manifestations of disease are typical and are represented by violaceous single tumors or multiple plaques present in sun-exposed cutaneous areas. BPDCN is issued from the malignant transformation of dendritic cell progenitors and is diagnosed using the classical immunophenotypes CD123, CD4 and CD56 in addition to specific membrane markers of plasmocytoid dendritic cells. BPDCN is an aggressive disease and is associated with a short survival. Upfront therapies involve either chemotherapy regimens in fit patients and CD123-targeted therapies, including interleukin-3 conjugated with diphtheria toxin (Tagraxofusp, SL-401), or Pivekimab sunirine, an anti-IL-3R-drug conjugate, for both fit and unfit patients. Targeted treatments limit the toxicities of chemotherapy and allow the bridging of a consistent proportion of patients to hematopoietic stem cell transplantation, the only treatment associated with potential long-term survival. Full article

Background: Acute lymphoblastic leukemia is the most prevalent childhood cancer and the leading cause of cancer mortality before the age of 20. Although therapeutic advances have significantly improved survival, children and adolescents treated for acute lymphoblastic leukemia remain vulnerable to infections, largely preventable by vaccination, due to humoral and cellular immune dysfunction induced by disease and treatment. Materials and Methods: This systematic review, based on electronic databases, aims to evaluate antibody levels associated with potential protective immunity against vaccine antigens for diphtheria, pertussis, tetanus, poliomyelitis, Haemophilus influenzae type b, measles, mumps, rubella, influenza, varicella-zoster virus, yellow fever, pneumococcal, and meningococcal diseases in children and adolescents treated for acute lymphoblastic leukemia after completion of chemotherapy. Results: A total of twenty-four studies published between 1981 and 2023 were included, comprising 1110 children and adolescents. Protective antibody levels ranged from 11% to 97% for diphtheria, 0% to 90% for pertussis, 20% to 100% for tetanus, and 11% to 95% for poliomyelitis. Haemophilus influenzae type b, protection ranged from 16.7% to 100%. Viral vaccines also showed heterogeneous responses, with protection rates of 25–79% for mumps, 16–86% for measles, 35–98% for rubella, and 23–75% for varicella-zoster virus. Antibody responses to pneumococcal and meningococcal vaccines were consistently low, with protection rates of 5–38% for pneumococcal studies and 12% in a single meningococcal study. Conclusions: This review found a consistent and clinically relevant loss of vaccine-induced immunity in children and adolescents treated for acute lymphoblastic leukemia. The recommendation of vaccine booster doses for this vulnerable population, irrespective of serological status, may represent a more practical approach to ensuring adequate post-chemotherapy treatment protection. Full article

Background/Objectives: Vaccination represents a significant achievement of public health and should be regarded not only as a protective measure against infectious diseases but also an active preventive intervention and a component of health promotion. Methods: This cross-sectional study assessed vaccination coverage among adults aged ≥60 years who attended a Primary Health Care Center during a predefined period of at least two months (November–December 2025) in a rural area of Crete, Greece, and examined determinants of immunization, including demographic, clinical, psychosocial, and health service utilization factors. The sample comprised 366 participants who consented to complete a structured questionnaire, primarily via interview, followed by verification of vaccination status through medical records. Results: High vaccination coverage was observed for influenza (82.5%), moderate coverage for pneumococcal (68.3%) and herpes zoster (56.0%) vaccines, and very low coverage for tetanus–diphtheria–pertussis booster doses (≈13%) and RSV vaccination (5.2%). For SARS-CoV-2, 96.2% received the three doses which were mandatory during the pandemic years. The overall Vaccination Coverage Score (VCS) averaged 43.1/100, while only 10.1% of participants achieved high coverage. Regression analysis showed that higher educational level, multimorbidity, and extensive use of health services were independently associated with better vaccination coverage (p < 0.05). Conclusions: The findings reveal fragmented vaccination patterns and underscore the need for systematic assessment of adult vaccination status within routine Primary Health Care. Targeted counseling, promotion of health literacy, and preventive vaccination strategies are expected to reduce vaccine-preventable morbidity and support healthy aging. Full article

Background: The end of the COVID-19 public health emergency of international concern (PHEIC) in May 2023 marked a transition from disruption to recovery and rebuilding of health systems. The WHO African Region entered this period with declining routine immunization coverage, widening inequities, and fragile surveillance systems. We conducted a critical narrative synthesis of post-PHEIC recovery and the transformation of immunization systems in the region from 2023 to 2025. Methods: We thematically analyzed publicly available data from the WHO and other sources using a systems-oriented framework covering immunization coverage, equity, vaccine introductions, disease control, governance, financing, and data systems. Results: Regional coverage for most antigens was restored to 2019 pre-pandemic levels by 2024, e.g., three doses of diphtheria-tetanus-pertussis-containing vaccines at 76%. However, progress remains insufficient to meet the Immunization Agenda 2030 (IA2030) target of 90% coverage. In addition, there were 6.7 million zero-dose children in the 2024 birth cohort (6.3% higher than the 6.3 million in 2019), concentrated in a few countries. The IA2030 target is a 50% reduction in the number of zero-dose children by 2030, compared to 2019. Recovery initiatives have restored services, while accelerated introductions (e.g., malaria vaccines introduced in 20 new countries in 2024–2025) signal renewed system momentum. Yet, progress has plateaued at pre-pandemic levels, reflecting structural constraints rather than sustained transformation. Concurrently, recurrent outbreaks of measles, yellow fever, and other vaccine-preventable diseases highlight persistent immunity gaps and surveillance limitations. Structural constraints (including financing fragility, subnational inequities, and system fragmentation) continue to limit sustained progress. Conclusion: This study offers important insights that can inform immunization policymaking in the WHO African Region and beyond. Current post-PHEIC trends reflect recovery without transformation. Achieving IA2030 targets will require a shift from broad coverage expansion to precision delivery approaches that prioritize zero-dose and underserved populations. Immunization must be positioned as a central pillar of primary health care and health security systems. Full article

Cancer remains one of the leading causes of morbidity and mortality worldwide, and despite major advances in surgery, chemotherapy, radiotherapy, and immunotherapy, important therapeutic limitations persist, including systemic toxicity, therapeutic resistance, and poor drug penetration into hypoxic tumor regions. These challenges have renewed interest in alternative biological strategies, particularly the use of bacteria and bacterial toxins as antitumor agents. Certain bacterial species possess intrinsic tumor-targeting properties, including the ability to selectively colonize hypoxic and necrotic regions of solid tumors that are poorly accessible to conventional therapies. This review provides a comprehensive analysis of the mechanisms underlying bacteria-mediated anticancer activity, including selective tumor colonization, direct oncolysis, immune activation, and toxin-mediated cytotoxicity. Both obligate anaerobes (e.g., Clostridium and Bifidobacterium) and facultative anaerobes (e.g., Salmonella, Escherichia coli, and Listeria monocytogenes) are examined for their tumor-targeting potential. In addition, we discuss the oncological applications of several bacterial toxins and toxin-derived therapeutic constructs, including Cytolysin A (ClyA), Clostridium difficile toxin B (TcdB), diphtheria toxin, Pseudomonas aeruginosa exotoxin A, and Clostridium perfringens enterotoxin (CPE). Emerging strategies such as recombinant immunotoxins and bacterial-directed enzyme prodrug therapy (BDEPT) are also reviewed. Finally, current translational challenges, including pharmacokinetic limitations, immune clearance, and biosafety considerations, are analyzed, highlighting future directions for integrating bacteria-based platforms into next-generation cancer therapies. This approach reflects the growing interest in microbial strategies for oncology and underscores the potential of bacteria and their toxins as innovative tools in the development of targeted anticancer therapies. Full article

Objective: Influenza and pertussis vaccines are recommended during pregnancy; however, uptake remains insufficient in many European countries, increasing the risk of preventable infections. Recent recommendations for maternal respiratory syncytial virus vaccination have been endorsed by scientific societies. This study evaluated maternal vaccination coverage, knowledge, attitudes, and factors influencing vaccine uptake among Lithuanian women. Methods: A retrospective cross-sectional online survey was conducted between 4 and 14 November 2025 in Lithuania among women aged 18–55 years with at least one previous pregnancy. The questionnaire contained 29 questions on sociodemographic characteristics, obstetric history, vaccination history, attitudes, and informational sources influencing decisions. Internal reliability was confirmed (Cronbach’s α = 0.83). Descriptive statistics were used to summarize the data. Associations between categorical variables were assessed using the Chi-square test or exact tests (Fisher’s exact or Fisher–Freeman–Halton). Binary and multivariable logistic regression analyses were performed to evaluate factors associated with self-reported vaccination uptake and the relationship between influenza and pertussis vaccination. Odds ratios with 95% confidence intervals were calculated. Statistical significance was set at p < 0.05. Results: A total of 241 women participated. Self-reported vaccination coverage during pregnancy was 28.7% for influenza, 43.8% for tetanus–diphtheria–pertussis, and 4.2% for respiratory syncytial virus. Physician’s recommendation was the strongest predictor: women advised to vaccinate were 17.0 times more likely to receive influenza, 16.5 times more likely to receive pertussis, while RSV vaccination occurred almost exclusively among women who reported receiving a physician’s recommendation. Higher uptake was associated with younger maternal age and university education. Reasons for declining vaccination were avoidance of medical interventions and concerns about safety or side effects. Conclusions: Maternal vaccination coverage in Lithuania remains low despite public funding and national recommendations. Strengthening provider communication, improving information strategies, and integrating vaccination counseling into routine antenatal care may increase uptake and enhance maternal and neonatal protection. Full article

Background: Transferrin receptor protein 1 (TfR1) plays a central role in cellular iron uptake and is frequently overexpressed in malignant tumor cells, rendering it an attractive target for tumor-directed therapy and drug delivery. Methods: A fully human single-chain variable fragment (scFv) antibody targeting TfR1, termed T8scFv, was isolated from a human scFv phage display library through three rounds of stringent biopanning and subsequently reformatted into a full-length IgG1 antibody (T8IgG1). Binding kinetics were characterized using Octet biolayer interferometry (BLI), while cellular binding and internalization were assessed by flow cytometry and immunofluorescence microscopy, respectively. T8IgG1 was further conjugated to DT3C, a recombinant truncated diphtheria toxin fusion protein, to evaluate its internalization-dependent cytotoxicity in vitro. Results: T8scFv exhibited nanomolar affinity for TfR1 (K_D = 214 ± 1 nM), which was substantially enhanced following conversion to the IgG1 format (T8IgG1, K_D = 18.5 ± 0.1 nM). T8IgG1 specifically recognized TfR1 on the surface of tumor cells and underwent efficient TfR1-mediated internalization. The T8IgG1-DT3C complex significantly reduced cell viability and induced apoptosis in K562 cells in vitro. Conclusions: These findings indicate that T8IgG1 is a moderate-affinity, internalizing anti-TfR1 antibody and highlight its potential as a promising candidate for TfR1-based targeted antitumor drug delivery systems. Full article

Background: Pemphigus diseases are rare autoimmune blistering disorders mediated by pathogenic autoantibodies directed mainly against desmoglein 1 and desmoglein 3. Although most cases are considered idiopathic, external triggers that can disrupt immune tolerance have been described. Vaccination has been discussed as a potential precipitating factor in autoimmune skin diseases. However, the relationship between vaccination and the induction of pemphigus-related autoantibodies has not been comprehensively summarized. Methods: We conducted a narrative review of all available studies published in the last 25 years identified through medical databases, excluding studies on COVID-19 vaccinations. Reports describing either new-onset pemphigus or exacerbation of preexisting pemphigus with a temporal association to vaccination were included. Clinical characteristics, vaccine type, latency period, direct immunofluorescence findings, and ELISA results for desmoglein autoantibodies were analyzed. In addition, we present our own clinical-laboratory experience illustrating this issue. Results: The current evidence consists predominantly of case reports and small case series. Published cases describe pemphigus vulgaris and pemphigus foliaceus occurring after vaccinations against influenza, hepatitis B, tetanus, diphtheria, pertussis, rabies, and other routinely administered immunizations. The latency period most often ranged from several days to a few weeks. Immunopathological findings were consistent with classical pemphigus diseases, including intercellular IgG deposits in the epidermis and circulating autoantibodies against desmoglein 1 and/or desmoglein 3. Our patient was a 78-year-old woman who developed cutaneous form of pemphigus vulgaris, diagnosed with direct immunofluorescence (DIF) and multiplex ELISA, 10 days after diphtheria–tetanus–pertussis vaccination. The patient had a positive family history of autoimmune blistering disease, namely mucous membrane pemphigoid. Conclusions: Based on the currently available evidence, a direct causal relationship between vaccination and pemphigus diseases cannot be established. Nevertheless, accumulated clinical and serological observations suggest that vaccination may act as a triggering factor in genetically or immunologically predisposed individuals, possibly by amplifying pre-existing subclinical autoreactive immune responses. Further population-based and mechanistic studies are required to clarify this association, while the overall benefits of vaccination remain substantial. Full article

Background: Liberia modernized vaccination data systems in 2023–2025 by piloting a District Health Information System (DHIS2)-based Digital Vaccination Registry (Electronic Immunization Registry, EIR) to address the limitations of paper-based workflows and of a proprietary COVID-19 electronic platform (offline gaps, lack of unique identifiers, performance issues and cost). Objective: To assess a pilot platform by evaluating training, registry use and device management, utility for routine immunization, vaccine logistics and Adverse Events Following Immunization (AEFI) data, and routine immunization data quality in the DHIS2 mobile application compared with paper registers. Methods: Using the Public Health Informatics Institute’s Collaborative Requirements Development Methodology, stakeholders defined requirements, trained users and implemented a pilot. Mixed methods were used; a mini data audit was performed, and qualitative data were collected across 19 facilities in Montserrado, Gbarpolu and Grand Bassa. Seventy-eight health workers were trained to use the DHIS2 mobile application. Results: The future state design replaces paper aggregation steps with real-time mobile entry to a national registry and dashboard. Dual entry persisted during high-volume periods. The mini data audit found discrepancies between facility paper registers and DHIS2-EIR entries for child enrollment data and, Bacillus Calmette Guérin and Diphtheria–Pertussis–Tetanus dose administration records Participants attributed these discrepancies to internet and device problems and challenges navigating the system. Participants requested a training manual, improved connectivity at point of service, integration with supportive supervision, additional staff and system features (field to record hospital number, automated next visit date, and vaccination status prompts). Conclusions: Lessons from the pilot will inform country-wide implementation, including planned linkage with electronic birth and death registration to enable a unique child identifier and reduce manual errors and delays. Full article

Escherichia coli, Streptococcus equi subsp. zooepidemicus, Klebsiella oxytoca, and Enterococcus durans are microorganisms capable of causing severe infections, particularly in patients with underlying comorbidities or immune dysfunction. We report a rare clinical case of a 65-year-old man with advanced cardiac and hepatic disease who developed severe diarrheal syndrome followed by septic shock, rapid clinical deterioration, and death. Microbiological examination of autopsy specimens from the intestinal wall and spleen identified Escherichia coli O128 with an enterotoxigenic profile (lt+, st+, eae−), together with Streptococcus equi subsp. zooepidemicus, Klebsiella oxytoca, and Enterococcus durans. Histopathological analysis demonstrated catarrhal enteritis with fibrinous deposits, mucosal edema, vascular congestion, and inflammatory infiltration. Although the microbiological findings were partly derived from autopsy material and postmortem bacterial translocation cannot be completely excluded, the concordance between clinical presentation, laboratory findings, and morphological changes supports the presence of a clinically significant infectious process. To our knowledge, this is the first reported human case of fatal polymicrobial infection involving these four pathogens. The case highlights the potential severity of polymicrobial infections in patients with cirrhosis-associated immune dysfunction and underscores the importance of integrated microbiological and molecular diagnostics for accurate etiological assessment. Full article