Search Results (404)

Background: In the Kingdom of Saudi Arabia, various COVID-19 vaccines were administered during the pandemic. However, region-specific real-word comparative data on their immunogenicity remain limited. This study aimed to assess the serological responses to Pfizer-BioNTech (BNT162b2), Moderna (mRNA-1273), and AstraZeneca (ChAdOx1 nCoV-19) vaccines in a diverse population living in KSA. Methods: This observational study included 236 adults recruited from vaccination sites in Riyadh. Participants provided serum samples at predefined intervals: before the first dose, after the first dose, after the second dose, and post-vaccination infection (if applicable). IgG and neutralising antibodies were quantified using ELISA assays. Demographic and vaccination data, and their associations with antibody responses, were evaluated. Results: At baseline, 75.4% of participants were positive for SARS-CoV-2 IgG, suggesting high prior exposure. Marked incremental increases in IgG levels were observed after each vaccine dose. Both Moderna and Pfizer elicited stronger responses, with Pfizer inducing the strongest early response and Moderna achieving the highest overall titres. Among IgG-positive individuals, neutralising antibodies were detected in 98.1%. There were no statistically significant differences by age or gender, although males tended to show higher mean titres. Heterologous vaccine schedules induced comparable or enhanced immunogenicity relative to homologous schedules, supporting their use in flexible immunisation strategies. Conclusions: All COVID-19 vaccines administered in Saudi Arabia elicited robust antibody responses, particularly the mRNA-based vaccines. Our findings support their continued use and justify varied vaccination approaches, including mix-and-match booster strategies, to enhance community immunity. Full article

Background: Immunisation remains one of the most effective and cost-efficient public health interventions for preventing infectious diseases in children. Despite global progress, Sub-Saharan Africa (SSA) continues to face challenges in achieving equitable immunisation coverage. Gender-related disparities, rooted in sociocultural and structural inequalities, significantly influence the prevalence of zero-dose and under-immunised children in the region. This review critically examines the gender-associated barriers to routine childhood immunisation in SSA to inform more inclusive and equitable health interventions. Methods: A critical literature review was conducted generally following some steps of the PRISMA-P and CRD guidelines. Using the Population–Concept–Context (PCC) framework, studies were selected that examined gender-related barriers to routine immunisation for children under five in Sub-Saharan Africa. Comprehensive searches were performed across PubMed, Google Scholar, and relevant organisational websites, targeting articles published between 2015 and 2025. A total of 3683 articles were retrieved, with 24 studies ultimately meeting the inclusion criteria. Thematic analysis was used to synthesise the findings. Results: Four major themes emerged: (1) women’s empowerment and autonomy, including limited decision-making power, financial control, and the impact of gender-based violence; (2) male involvement and prevailing gender norms, where patriarchal structures and low male engagement negatively influenced vaccine uptake; (3) socioeconomic and structural barriers, such as poverty, geographic inaccessibility, maternal workload, and service availability; and (4) education, awareness, and health system responsiveness. Conclusions: Gender dynamics have a significant impact on childhood immunisation outcomes in Sub-Saharan Africa. Future policies must integrate these insights to improve immunisation equity and reduce preventable child morbidity and mortality across the region. Full article

Background/Objectives: Enterovirus A71 (EV-A71) and coxsackievirus A16 (CVA16) are major causative agents of hand, foot and mouth disease (HFMD), often co-circulating and occasionally undergoing genetic recombination. While natural recombinants often involve genomic regions encoding non-structural proteins, their effects on replication and pathogenesis remain unclear. Methods: To address this, four chimera viruses (Chi-CCE, Chi-ECE, Chi-EEC, and Chi-CEC) were constructed with 5′UTR, capsid P1, and non-structural P2 and P3 genes, from CVA16 (denoted as C) or EV-A71 (denoted as E). These chimeras were tested for replication kinetics and cytopathic effects in rhabdomyosarcoma cells while in vivo virulence and protection efficacy were evaluated using a newborn BALB/c mouse model. Results: All chimeric viruses remained viable and exhibited higher replication than CVA16. In vivo, all chimeric viruses were avirulent except Chi-CCE and CVA16, which showed high virulence and viral titres in the brains and limbs of infected newborn mice. This suggests that 5′UTR and capsid P1 genes of CVA16 are critical genetic determinants of virulence. Notably, only the anti-inflammatory cytokine IL-10 was elevated, suggesting potential immune modulation during infection. Inactivated Chi-CCE immunisation conferred 100% protection against lethal CVA16 or mouse-adapted EV-A71 challenge revealing its potential as a bivalent vaccine candidate. Conclusions: Our study demonstrates that recombination between CVA16 and EV-A71 influences viral virulence and protection efficacy with implications for future development of multivalent vaccines. Full article

Introduction: Little is known about the quality of care for patients with hypertension in primary health care (PHC) facilities in South Africa, where most people receive care. Objectives: To test 46 quality indicators, developed previously, to assess and improve care; to assess the indicators’ clinimetric properties; and to recommend improvement strategies. Methods: A descriptive cross-sectional clinical audit in a purposive sample of 12 South African PHC clinics involving a retrospective review of 295 patient medical records. Results: A total of 45 of the 46 indicators were tested in the main sample (n = 295), of which 9 indicators could not be applied. Of the 36 applicable indicators, 22 could be applied and measured for ≥75% of the sample, while 14 were applicable to ≤50% of the sample. Only five indicators showed a quality of care score for ≥75% of patients. Overall, 82% and 92% of the sample had their blood pressure (BP) recorded in the last 12 months or in the previous 5 years for those aged >40, respectively, and 53.2% had a controlled BP. In the last 12 months, 30% of patients had a cholesterol record, 30% had their BMI recorded, 17% had a hypertension review with a medical practitioner, and 12% had received lifestyle advice. Only 38% received all clinically indicated antihypertensive medicines at their last visit. Conclusion: There were gaps in the quality of care for patients with hypertension, demonstrating the need for greater adherence to evidence-based guidelines, better data quality, and the use of electronic health information systems. Twenty-two indicators are recommended to address these gaps and improve the quality of care, patient outcomes, and the health care system. Full article

This study focuses on the Unified Health System (SUS) in five regions of the state of Rio de Janeiro, Brazil, one of Brazil’s most important states, as part of a comprehensive analysis of a research project, which has generated publications in earlier phases. The objective was to assess users’ perceptions of SUS in terms of access to and the quality of public health services, including primary care and pharmaceutical services. A cross-sectional study was conducted using a structured questionnaire comprising 66 questions, administered to a purposive sample of 1000 participants between August 2023 and August 2024. Data were analyzed using Pearson’s chi-square test with R software version 4.3. Among the participants, 54.5% were female, 62.5% were aged between 26 and 60 years, and 29% reported having private health insurance. Vaccination services were the most frequently used SUS service (25.1% of respondents). Participants who reported more frequent use of SUS services rated access more positively than those who used them less frequently (p = 0.002). The regions that evaluated SUS access and quality most favorably were Middle Paraíba and the metropolitan region, while the Coastal Lowlands region received the most negative assessments. Participants with lower socioeconomic status gave more favorable evaluations of access to public health services (p = 0.001). These findings highlight concerns about access to, and the quality of, SUS healthcare services and regional disparities in users’ perceptions of SUS services in Rio de Janeiro. The results underscore the importance of social participation as a key element in the evaluation and continuous improvement of responsive public healthcare. Full article

Argasid ticks Ornithodoros erraticus and Ornithodoros moubata are major vectors of zoonotic pathogens, including the African swine fever virus and relapsing fever Borrelia spp., and their control is essential to reduce disease transmission. In this study, we evaluated the immunogenicity and protective efficacy of four Ornithodoros tick antigens formulated as mRNA–lipid nanoparticles (mRNA-LNPs): OeSOD, OeTSP1, OmPLA2, and Om86. Rabbits were immunised with three doses of each mRNA-LNP construct, and immune responses and tick biological parameters were assessed following infestation with both tick species. All mRNA-LNP constructs induced antigen-specific IgG responses that recognised native proteins in tick saliva and midgut extracts. Vaccination resulted in significant reductions in female oviposition and fertility, which correlated with antibody levels, and yielded protective efficacies of 21.9–41.6% against O. moubata and 23.1–41.6% against O. erraticus. Notably, the mRNA-LNPs of OeSOD and OeTSP1 outperformed their recombinant counterparts against O. moubata, and Om86 mRNA-LNP conferred markedly improved protection against both O. moubata and O. erraticus. These findings highlight the potential of mRNA-LNP vaccines to induce effective anti-argasid tick immunity and provide a promising platform for the development of sustainable strategies to control argasid ticks and associated pathogens. Full article

Background: Indonesia launched a nationwide school-based HPV immunization program in August 2023. Despite this, regional disparities in vaccine uptake persist. Therefore, we undertook a study in North Sumatra Province to assess HPV vaccination coverage and analyze the main factors affecting the uptake of HPV vaccination. Methods: This study employed a mixed-methods approach and was carried out in Medan and Deli Serdang of North Sumatra Province. Quantitative data were used to examine HPV coverage rates among school-aged girls in 2024, while qualitative interviews with parents, teachers, and health officers explored administrative, social, and behavioral barriers and facilitators. Results: In 2024, HPV vaccine coverage in Deli Serdang reached 62.09%, while Kota Medan lagged behind at just 27.20%. High-coverage schools in the Galang subdistrict benefited from proactive engagement between Puskesmas (community health clinics) and parents. In contrast, lower-coverage areas experienced logistical and communication challenges. Parents expressed a preference for face-to-face communication over written consent forms and emphasized the importance of clear, empathetic messaging. Conclusions: The stark contrast in coverage—particularly the low uptake in urban Kota Medan—highlights the need for more responsive and localized implementation strategies. Strengthening direct communication, addressing administrative inefficiencies, and fostering trust through tailored community engagement are critical. These findings suggest a need for targeted improvements in urban settings and further research across diverse regions to inform policy development and strategies for improved coverage of HPV vaccinations. Full article

The pandemic spared most children and adolescents in Ghana from severe clinical disease, but it exposed long-standing gaps in services and protection methods. Methods: We conducted a desk-based narrative review of peer-reviewed studies, national and international reports, and grey literature from January 2020 to May 2025. The evidence was organised across eight domains of child and adolescent well-being. Across mental health, gambling and other risky behaviours, access to health services, economic hardship and child labour, nutrition, education, early childhood development, and WASH, the pandemic disrupted essential services and social safety nets. Examples include declines in routine care and immunisation, wider digital exclusion during remote learning, a rise in child labour linked to income loss, and persistent hygiene constraints. Preparedness in Ghana should focus on mental health, digital inclusion, early childhood services, and strong social protection. Ghana’s specific empirical data are uneven, so we triangulate peer-reviewed evidence with official reports, appraised the grey literature, and calibrated claims to the strength of sources. Full article

Influenza remains a major health threat due to its high contagiousness and global spread, affecting not only humans but also agricultural livestock and wild animals through transmission via migratory birds. Despite over 70 years of vaccination, influenza still creates epidemics and pandemics, and the ongoing use of vaccination is an essential but currently insufficient strategy. In this study, we assessed the immunogenicity and efficacy of an AP205 virus-like particle (VLP) carrying the HA head domain of the A/PR8/H1N1 strain, administered intranasally and subcutaneously in mice. For this purpose, the entire head region of A/PR8/H1N1 was genetically integrated into a sterically improved version of AP205, which exhibits capsid monomers fused into a dimer, thereby offering inexpensive and scalable production processes. The vaccine induced strong systemic anti-HA IgG and IgA antibodies via both routes, with no significant difference in the levels of IgG. Both immunisation strategies induced protection against a lethal challenge with H1PR8 mouse-adapted influenza virus. The findings demonstrate the potential of the AP205 VLP platform for HA1-based influenza vaccines and its applicability for controlling influenza in both humans and livestock. Full article

We aimed to explore SARS-CoV-2 evolution during in vitro neutralisation using next generation sequencing, and to determine whether sera from individuals immunised with two doses of the Pfizer-BioNTech vaccine (BNT162b2) were as effective at neutralising the variant of concern (VOC) Delta (B.1.617.2) compared to the earlier lineages Beta (B.1.351) and wild-type (A.2.2) virus. Using a live-virus SARS-CoV-2 neutralisation assay in Vero E6 cells, we determined neutralising antibody titres (nAbT) against three SARS-CoV-2 strains (wild type, Beta, and Delta) in 14 participants (vaccine-naïve (n = 2) and post-second dose of BNT162b2 vaccination (n = 12)), median age 45 years [IQR 29–65]; the median time after the second dose was 21 days [IQR 19–28]. The determination of nAbT was based on cytopathic effect (CPE) and in-house quantitative reverse transcriptase real-time quantitative polymerase chain reaction (RT-qPCR) to confirm SARS-CoV-2 replication. A total of 110 representative samples including inoculum, neutralisation breakpoints at 72 h, and negative and positive controls underwent genome sequencing. By integrating live-virus neutralisation assays with deep sequencing, we characterised both functional antibody responses and accompanying viral genetic changes. There was a reduction in nAbT observed against the Delta and Beta VOC compared with wild type, 4.4-fold (p ≤ 0.0006) and 2.3-fold (p = 0.0140), respectively. Neutralising antibodies were not detected in one vaccinated immunosuppressed participant and the vaccine-naïve participants (n = 2). The highest nAbT against the SARS-CoV-2 variants investigated was obtained from a participant who was vaccinated following SARS-CoV-2 infection 12 months prior. Limited consensus level mutations occurred in the various SARS-CoV-2 lineage genomes during in vitro neutralisation; however, consistent minority allele frequency variants (MFV) were detected in the SARS-CoV-2 polypeptide, spike (S), and membrane protein. Findings from countries with high COVID-19 incidence may not be applicable to low-incidence settings such as Australia; as seen in our cohort, nAbT may be significantly higher in vaccine recipients previously infected with SARS-CoV-2. Monitoring viral evolution is critical to evaluate the impact of novel SARS-CoV-2 variants on vaccine effectiveness, as mutational profiles in the sub-consensus genome could indicate increases in transmissibility and virulence or suggest the development of antiviral resistance. Full article

Background: Children with inflammatory bowel disease (IBD) are at heightened risk for vaccine-preventable infections because of underlying immune dysregulation and long-term immunosuppressive therapy. Despite published guidelines affirming vaccine safety, real-world coverage remains suboptimal. It is a pilot, single-country survey designed to explore baseline knowledge and practices regarding vaccination in paediatric IBD within a specific local healthcare context. Objective: The objective of this study is to evaluate the knowledge, attitudes, and practices of paediatric gastroenterologists (PGs) regarding the immunisation of children with IBD. Methods: We conducted an exploratory pilot, cross-sectional survey of paediatric gastroenterologists in Russia, focusing on immunisation knowledge and practical barriers in routine care. A cross-sectional, anonymous online survey was distributed to PGs nationwide between January 2022 and April 2022. The online questionnaire explored demographic characteristics, awareness of international recommendations, perceptions of vaccine safety at various disease and treatment stages, and routine vaccination practices. Responses were analysed with non-parametric statistics (α = 0.05). In a parallel prospective cohort, the vaccination certificates of 98 paediatric IBD patients (January 2022–April 2023) were audited to quantify real-world coverage. Results: Fifty-one PGs completed the survey. Forty-one per cent agreed that vaccines do not provoke IBD flares, while 17.6% considered live vaccines acceptable during immunosuppressive remission. Nearly one-third (32%) did not personally oversee immunisation, and 18% occasionally discouraged vaccination during therapy. Only 35.3% deemed baseline serology essential before starting immunosuppression; 46.5% supported antibody checks immediately prior to vaccination. The certificate audit revealed a full schedule completion rate of 66.3% for measles–mumps–rubella and 74.2% for hepatitis B, contrasting with parental reports of 82.3% complete coverage. Conclusions: Knowledge gaps, limited guideline awareness, and parental concerns contribute to suboptimal vaccination of paediatric IBD patients. Targeted educational initiatives, clearer shared-care pathways, and routine certificate audits are needed to close the coverage gap and reduce infection-related morbidity. Findings are hypothesis-generating and reflect local practice; as a pilot study, results should be interpreted with caution and may not generalise beyond similar settings. Full article

Background/Objectives: Pneumococcal serotypes 1 and 5 are associated with invasive pneumococcal disease (IPD). However, data on the circulation of these serotypes in Asia following the introduction of the pneumococcal conjugate vaccine (PCV) is limited. The Lao People’s Democratic Republic (Lao PDR) introduced PCV13 into its national immunisation programme in 2013. We undertook a serosurvey to assess the IgG responses to serotypes 1 and 5 from a convenience sample of children aged under 5 years in Vientiane, Lao PDR. Methods: This cross-sectional analysis used a convenience sample of the close contacts of children under five years old who had been hospitalised with acute respiratory infections between 2013 and 2016 in Vientiane, Lao PDR. Serotype-specific IgG concentrations to serotypes 1 and 5 were measured using a modified WHO ELISA method. Results: A total of 214 participants were included, 130 of whom were unvaccinated and 84 were vaccinated with PCV13. Compared to unvaccinated participants, a higher number of PCV-vaccinated participants met the IgG threshold for IPD (≥0.35 μg/mL) [41.5% (54/130) vs. 71.4% (60/84)] for serotype 1. In contrast, for serotype 5, a similar number of participants in the PCV-vaccinated and unvaccinated group met the IgG threshold for IPD (85.7% (72/84) vs. 82.3% (107/130). Among unvaccinated children, serotype 1 IgG levels peaked at 12 and 23 months at 0.49 µg/mL (95% CIs: 0.25–0.96), while serotype 5 IgG levels were similar across age groups, ranging from 0.55 to 0.79 µg/mL. Conclusions: Our findings indicate the considerable circulation of serotypes 1 and 5 within the community in Lao PDR. Ongoing surveillance is important for informing PCV vaccination strategies. Full article

Introduction: Polio supplementary immunisation activities (SIA) are implemented to rapidly increase vaccination coverage and interrupt the transmission of poliovirus in a specified geographical area. Polio SIA complements routine immunisation and is crucial for the eradication of the disease by increasing population immunity. However, several contextual factors (i.e., implementation determinants) can influence the success or failure of polio SIA implementation; as such, understanding their dynamics can enhance proactive planning for practice improvement. This study aimed to explore and map the contextual factors of polio SIA implementation in the African region using a critical systems thinking approach. Methods: A rapid review of published and grey literature was conducted. The search included the Global Polio Eradication Initiative library for programmatic reports and two databases (PubMed and Google Scholar). Data extraction was performed using a structured tool. Thematic analysis was performed to categorise the identified contextual factors according to the domains and constructs of the Consolidated Framework for Implementation Research (CFIR). Then, a causal loop diagram (CLD) was used to map the linkages between the identified factors. Results: A total of seventy-eight contextual factors across the five CFIR domains were identified: three for innovation, twenty for outer setting, sixteen for inner setting, twenty-six for individuals, and thirteen for the implementation process. A system map of all the factors using CLD revealed multiple contingent connections, with eleven reinforcing loops and four balancing loops. Conclusions: This study identified the multilevel nature of the contextual factors that influence polio SIA, including their dynamics. The integration of CLD and CFIR in this study offers critical insights into the potential feedback loops that exists between the contextual factors which can be used as leverage points for policy and practice improvements, including tailoring strategies to enhance polio campaign implementation effectiveness, especially with the expanded use of the novel Oral Polio Vaccine type 2 (nOPV2) across countries in the region. Full article

Background and Objectives: Romania has experienced the highest measles incidence rate in the European Union since late 2023, driven by suboptimal measles–mumps–rubella (MMR) uptake. Contemporary data on bedside predictors of clinical deterioration are scarce. The objective was to characterise demographic, clinical and laboratory differences between severe and non-severe measles and derive a multivariable model for intensive-care-unit (ICU) admission. Methods: We undertook a retrospective cohort study at the “Victor Babeș” University Hospital for Infectious Diseases, Timișoara. All admissions from 1 November 2023 to 15 May 2025 with serological or RT-PCR confirmation and a complete baseline laboratory panel were included. Descriptive statistics compared ward-managed versus ICU-managed patients; independent predictors of ICU transfer were identified through logistic regression that incorporated age, vaccination status, leukocyte count, C-reactive protein (CRP) and interleukin-6 (IL-6). Results: Among 455 patients (median age 3.0 y, interquartile range [IQR] 1.0–7.0), 17 (3.7%) required ICU care. Vaccine coverage was 18.0% overall and 0% among ICU cases. Compared with ward peers, ICU patients exhibited higher leukocyte counts (8.1 × 10⁹ L vs. 6.0 × 10⁹ L; p = 0.003) and a near-five-fold elevation in IL-6 (18 pg mL vs. 4 pg mL; p < 0.001), while CRP, procalcitonin and fibrinogen were similar. ICU admission prolonged median length of stay from 5 days (IQR 4–7) to 8 days (5–12; p = 0.004). In multivariable modelling, IL-6 remained the sole independent predictor (odds ratio [OR] 1.07 per pg mL; 95% confidence interval [CI] 1.03–1.12; p = 0.001); the model’s AUC was 0.83, indicating good discrimination. Complete separation precluded reliable estimation of the protective effect of vaccination, but no vaccinated child required ICU care. Conclusions: A simple admission panel centred on IL-6 accurately identified Romanian measles patients at risk of critical deterioration, whereas traditional markers such as CRP and leukocyte count added little incremental value. Even a single documented MMR dose was associated with the complete absence of ICU transfers, underscoring the urgent need for catch-up immunisation campaigns. Integrating IL-6-guided triage with intensified vaccination outreach could substantially reduce measles-related morbidity and health-system strain in low-coverage EU settings. Full article

Background/Objectives: The middle-income countries (MICs) in the Middle East and North Africa (MENA) region face multifaceted challenges—including fiscal constraints, conflict, and vaccine hesitancy—that impede the timely introduction of critical vaccines. This study examines the status, barriers, and facilitators to introducing three critical vaccines—human papillomavirus vaccine (HPV), pneumococcal conjugate vaccine (PCV), and rotavirus vaccine (RV)—across seven MENA MICs, to identify actionable solutions to enhance vaccine uptake and immunisation coverage. Methods: Using the READ methodology (ready materials, extract, analyse, and distil data), this review systematically analysed policy documents, reports, and the literature on the introduction of HPV, PCV, and RV vaccines in seven MENA MICs. A data extraction framework was designed to capture the status of vaccine introduction and barriers and facilitators to introduction. Findings and data gaps were validated with stakeholder consultations. Results: Of the seven study countries, progress in introducing PCV and RV has been uneven across the region (five countries have introduced PCV, four have introduced RV, and only a single country has introduced HPV at time of writing), hindered by vaccine hesitancy, fiscal challenges, and insufficient epidemiological data. Morocco is the only country to introduce all three vaccines, while Egypt has yet to introduce any. Other common barriers include the impact of conflict and displacement on healthcare infrastructure, delayed introduction due to the 2020 COVID-19 pandemic, and limited local production facilities and regional cooperation. In addition, not all countries eligible for Gavi MICs support have applied. These findings provide a roadmap for policymakers to accelerate equitable vaccine introduction in the MENA region. Conclusions: Targeted efforts, such as addressing fiscal constraints, improving local manufacturing, tackling gender barriers, and fostering public trust, paired with regional collaboration, can help bridge gaps and ensure no community is left behind in preventing vaccine-preventable diseases. Full article