Search Results (377)

Background: Despite decades of high childhood vaccination coverage, pertussis has re-emerged in the Autonomous Province of Vojvodina (AP Vojvodina), Serbia. We aimed to describe the temporal, seasonal, and age-specific patterns of pertussis in AP Vojvodina and to analyze trends by vaccination status in order to highlight changes in epidemiology and potential gaps in vaccine-induced protection. Methods: We retrospectively analyzed 2796 pertussis cases reported between January 1997 and December 2024, examining temporal, seasonal, and age-specific trends, stratifying by vaccination status across four consecutive periods (1997–2003, 2004–2010, 2011–2017, and 2018–2024). Results: Throughout the 28-year period, after low and sporadic cases in the pre-2012 period, a dramatic rise was observed in 2014, 2017, and 2018, culminating in the highest annual number of reported cases in 2024 (1011 cases). Throughout this period, primary vaccination coverage with the DTwP/DTaP three-dose series ranged between 91% and 98%, while first booster coverage gradually declined from 98% in the early 2000s to 83% in 2024. Regarding seasonality, a sharp increase in cases began in 2012, peaking in November 2023 (>350 cases) and early 2024 (312 in January, 268 in February), with a seasonal shift from summer peaks in the 2011–2017 period to higher incidence rates during colder months more recently. Adolescents aged 10–14 years had the highest cumulative incidence (1149.4/100,000), followed by infants under 12 months (978.5/100,000), despite the latter representing fewer absolute cases. The proportion of pertussis in fully vaccinated individuals rose from 6.3% (1997–2003) to 49.7% (2018–2024). Conclusions: These findings suggest that booster immunization in adolescence and routine maternal vaccination during pregnancy could reduce transmission, particularly to infants. Enhanced surveillance and updated immunization policies are critical to mitigating future pertussis outbreaks. Full article

Background/Objectives: Medical and nursing students, as future healthcare professionals, influence public trust and vaccine acceptance. Knowledge gaps or misconceptions regarding immunization may undermine their confidence and effectiveness in addressing vaccine hesitancy. This study explores perceptions and attitudes toward childhood vaccination among Bulgarian healthcare students and factors shaping these outcomes. Methods: A cross-sectional survey was conducted in 2024, using an online self-administered questionnaire completed by 374 medical and nursing students. Descriptive statistics were used to analyze vaccine-related responses, comparing attitudes between healthcare programs and education years. Binomial logistic regression was applied to identify predictors of support for mandatory vaccination, first considering demographic and academic variables, and then adding students’ beliefs and common misconceptions. Results: Medical students showed more positive attitudes toward vaccination than nursing students, with 96.8% of medical students versus 89.4% of nursing students believing vaccines are effective (p = 0.005). Students in advanced years demonstrated stronger belief in vaccine effectiveness (p = 0.038). Additionally, misbeliefs about the measles vaccine causing autism decreased significantly, with most students in higher years rejecting this misconception (p = 0.009). Logistic regression revealed that belief in following the vaccine schedule (OR = 22.71; p < 0.001) and confidence in vaccine effectiveness (OR = 10.20; p < 0.001) were the strongest predictors of support for mandatory vaccination, with attitudinal factors explaining over half of the variance. Conclusions: Healthcare students’ attitudes about vaccination influence public health outcomes, as their perspectives reflect experience and beliefs. Targeted vaccine education helps address misconceptions and improve vaccination rates. Full article

High rates of childhood vaccination defaulting remain a significant barrier to achieving full vaccination coverage in sub-Saharan Africa, contributing to preventable morbidity and mortality. This study evaluated the utility of machine learning algorithms for predicting childhood vaccination defaulters in Ghana, addressing the limitations of traditional statistical methods when handling complex, high-dimensional health data. Using a merged dataset from two malaria vaccine pilot surveys, we engineered novel temporal features, including vaccination timing windows and birth seasonality. Six algorithms, namely logistic regression, support vector machine, random forest, gradient boosting machine, extreme gradient boosting, and artificial neural networks, were compared. Models were trained and validated on both original and synthetically balanced and augmented data. The results showed higher performance across the ensemble tree classifiers. The random forest and extreme gradient boosting models reported the highest F1 scores (0.92) and AUCs (0.95) on augmented unseen data. The key predictors identified include timely receipt of birth and week six vaccines, the child’s age, household wealth index, and maternal education. The findings demonstrate that robust machine learning frameworks, combined with temporal and contextual feature engineering, can improve defaulter risk prediction accuracy. Integrating such models into routine immunization programs could enable data-driven targeting of high-risk groups, supporting policymakers in strategies to close vaccination coverage gaps. Full article

Background: Despite the widespread implementation of childhood vaccination programmes, hepatitis B virus (HBV) infection remains an ongoing occupational risk for healthcare students. In multi-ethnic and international university settings, differences in vaccination programmes and immune responses must be considered. This retrospective study aimed to assess the prevalence of protective levels of anti-HBs among medical students at an international university in Rome, exploring associations with demographic and vaccination-related factors. Methods: Data were collected from routine occupational health surveillance conducted in 2023. Anti-HB titres were measured in 507 students, and information on age, sex, country of birth, age at vaccination, and time since the last dose was analysed. Results: Overall, 55.0% of students had antibody levels of at least 10 mIU/mL, indicating serological protection. Higher seroprotection rates were observed among students vaccinated in the first year of life compared to those vaccinated later. A significant decline in antibody titres was also associated with longer intervals since vaccination. Students born outside Europe tended to show lower levels of protection. Conclusions: These results emphasise the importance of screening future healthcare professionals and continuously monitoring antibody titres to help reduce HBV infections. Full article

Background: The Bacille Calmette–Guérin (BCG) vaccine is part of the Extended Programme on Immunization (EPI) and as such is generally administered at birth. The global introduction of BCG not only protected many vaccinated infants against severe complications of tuberculosis but also resulted in markedly reduced overall childhood mortality. Studies in human adults determined that BCG vaccination induces epigenetic reprogramming of innate immune cells (also known as trained immunity) and can also enhance T cell responses to both mycobacterial and non-mycobacterial antigens. Goal and Methods: The current study tested the hypothesis that BCG immunization similarly impacts the functionally distinct infant immune system. Towards this goal, we applied RNA sequencing to assess transcriptome changes in circulating CD4⁺ T cells of Malawian infants prior to and 2 to 13 weeks after BCG immunization. Results: In the first three months of life, transcriptome changes of infant CD4 T cells implied a functional shift towards T helper 1 and Th17 immunity. Vaccination with BCG resulted in additional modulation of the CD4 T cell transcriptome and differentially expressed genes could be linked to metabolomic function. Conclusions: These findings are consistent with data reported in BCG vaccinated adults and contribute to the understanding of molecular changes in infant CD4 T cells that may explain the improved capacity of the infant immune system to respond to pathogens after BCG vaccination. Full article

Human metapneumovirus (hMPV), a member of the Pneumoviridae subfamily, has emerged as a significant etiological agent of acute respiratory tract infections across diverse age groups, particularly affecting infants, the elderly, and immunocompromised individuals. Since its initial identification in 2001, hMPV has been recognized globally for its seasonal circulation pattern, predominantly in late winter and spring. hMPV is a leading etiological agent, accounting for approximately 5% to 10% of hospitalizations among pediatric patients with acute respiratory tract infections. hMPV infection can result in severe bronchiolitis and pneumonia, particularly in young children, with clinical manifestations often indistinguishable from those caused by human RSV. Primary hMPV infection typically occurs during early childhood; however, re-infections are frequent and may occur throughout an individual’s lifetime. hMPV is an enveloped, negative-sense RNA virus transmitted through respiratory droplets and aerosols, with a 3–5-day incubation period. The host immune response is marked by elevated pro-inflammatory cytokines, which contribute to disease severity. Advances in molecular diagnostics, particularly reverse transcription–quantitative polymerase chain reaction (RT-qPCR) and metagenomic next-generation sequencing (mNGS), have improved detection accuracy and efficiency. Despite these advancements, treatment remains largely supportive, as no specific antiviral therapy has yet been approved. Promising developments in vaccine research, including mRNA-based candidates, are currently undergoing clinical evaluation. This review synthesizes current knowledge on hMPV, highlighting its virological, epidemiological, and clinical characteristics, along with diagnostic advancements and emerging therapeutic strategies, while underscoring the critical role of continued research and sustained preventive measures—including vaccines, monoclonal antibodies, and non-pharmaceutical interventions—in mitigating the global burden of hMPV-related disease. Full article

Background/Objectives: Maintaining high childhood vaccination coverage is essential to prevent outbreaks of vaccine-preventable diseases. In Italy, Law No. 119/2017 introduced mandatory childhood immunizations, leading to significant improvements. However, the COVID-19 pandemic disrupted routine services, potentially jeopardizing these gains. This study aimed to evaluate national and regional trends in vaccine coverage across three phases: post-mandate (2015–2016 vs. 2017–2019), pandemic (2017–2019 vs. 2020–2021), and post-pandemic recovery (2020–2021 vs. 2022–2023). Methods: National and regional administrative data on vaccination coverage at 24 months of age were obtained from the Italian Ministry of Health. Temporal trends were analyzed using Joinpoint regression to estimate annual percent changes (APCs), and absolute changes in coverage (Δ) were calculated across defined periods. Pearson correlation coefficients were used to assess associations between baseline coverage and subsequent changes. Results: After the 2017 mandate, coverage increased significantly for varicella (APC = +28.6%), MenB (+22.6%), and measles (+3.4%). Regionally, varicella coverage rose by up to +58.4% in Emilia-Romagna and measles by +11.1% in Campania. During the pandemic, coverage declined for polio (−2.4% in the South) and measles (−6.2% in Abruzzo), while MenB increased in regions with lower initial uptake (r = −0.918, p < 0.001). Post-pandemic, coverage rebounded, with varicella improving by +20.1% in central regions and measles by +13.9% in Abruzzo. A strong inverse correlation between baseline coverage and improvement was observed for varicella across all periods (r from −0.877 to −0.915). Conclusions: Mandatory vaccination policies led to substantial coverage improvements, and despite the disruption caused by the pandemic, recovery trends were observed for most vaccines. The consistent association between low baseline coverage and stronger gains highlights the resilience of the system, but also the ongoing need for regionally tailored strategies to reduce geographic disparities and ensure equitable immunization across Italy. Full article

Rotavirus alphagastroenteritidis (R. alphagastroenteritidis) remains the leading cause of pediatric diarrhea. Although Angola introduced Rotarix^®, the human monovalent R. alphagastroenteritidis vaccine since 2014 as part of its routine childhood immunization program, no follow-up study has been conducted. The aim of this study was to evaluate the distribution of R. alphagastroenteritidis genotypes among children under five years of age, hospitalized with acute gastroenteritis (AGE), after the introduction of the rotavirus vaccine. To achieve this goal, stool samples collected between 2021 and 2022 from children under 5 years of age diagnosed with AGE at six hospitals in Luanda Province were analyzed. The R. alphagastroenteritidis-antigen immunochromatographic test (SD Bioline™, Abbott, Chicago, IL, USA) was performed, and 121 positive samples were genotyped. Ten samples were randomly selected for further Sanger sequencing. The results showed that the G9P[6] was the most prevalent genotype (17.3%), followed by G9P[8] (16.5%), G2P[4] (14.9%), G3P[6] (13.2%), G8P[6] (11.5%), and less frequently G12P[8] (9.1%), G1P[6] (4.1%), and G1P[8] (2.5%). The genotype combinations G3P[6], G8P[6], and G12P[8] were detected for the first time in Luanda Province. In conclusion, the emergence of new genotype combinations supports the need for continuous surveillance to identify the trend in R. alphagastroenteritidis infection and the emergence of new strains circulating in Luanda Province in the post-vaccination period. Full article

Immunization coverage is a key public health indicator reflecting healthcare accessibility and socio-economic conditions. This study employs Principal Component Analysis (PCA) to construct composite development scores and analyze their relationship with immunization coverage for measles and diphtheria-tetanus-pertussis (DTP) vaccines across 195 countries (2000–2021). The analysis comprises a training period (2000–2015) for score development and a test period (2016–2021) for validation. Variables were selected based on correlation with immunization coverage and standardized before PCA extraction. PC1, the principal component explaining the largest variance, was identified as a key indicator of development disparities. Findings reveal that higher PC1 scores (lower socio-economic development) are associated with reduced immunization rates, while lower PC1 scores (higher socio-economic development) correspond to greater coverage, a trend consistent across both periods. Geospatial analysis highlights stark disparities, particularly in sub-Saharan Africa and South Asia, whereas North America, Europe, and East Asia maintain significantly higher coverage. These results provide policy-relevant insights, demonstrating the utility of PCA-derived scores for resource allocation and targeted interventions. Full article

Introduction: An effective vaccination strategy requires monitoring serotype changes by geography and age. This study analyzed Streptococcus pneumoniae serotypes in healthy children under 6 years of age vaccinated with PCV10 in Bulgaria from October 2021 to May 2025. Methods: A total of 569 children were screened for the lytA and cpsA genes viareal-time polymerase chain reaction (real-time PCR). Positive samples were typed using relevant kits, and 76 serotypes/serogroups of S. pneumoniae were identified. Results: Nasopharyngeal swabs from 232 children (40.8%) were found to carry S. pneumoniae, and a total of 255 serotypes were detected, with 19B/19C (17.2%), 6C (10.7%), and 15B/15C (9.8%) being the most prevalent. Of these, 91 serotypes (15.9%) were included in at least one vaccine, while the remaining 164 serotypes (25.4%) were not. The carriage rate reduced to 22% in 2023 but increased to 47% in 2024. Overall, younger children had lower carriage rates (p < 0.05), with serotype 6C being more common in children under 12 months of age (25%). Approximately 9.1% of pneumococcal carriage cases involved co-detected serotypes, with significantly higher co-detection rates for 19B/19C, 15B/15C, 10B, 10F/C, 23B, 7C/40, 23A, and 24A compared with mono-detection rates (p < 0.05). Conclusions: 19B/19C, 6C, 15B/15C, and 19A were identified as the main serotypes. Children over 3 years of age were also more likely to carry multiple pneumococci. These findings emphasize the need to reassess childhood vaccination strategies to curb the spread of antibiotic-resistant serotypes. Full article

Background: Childhood cancer survivors (CCSs) often experience impaired humoral immunity because of cancer treatments that increase their susceptibility to vaccine-preventable diseases. This study aimed to assess the seroprevalence of tetanus and rubella antibodies in CCSs compared to healthy, age-matched controls. Additionally, we explored the impact of cancer treatments on vaccine-induced immunity, examined the extent of revaccination after treatment completion, and evaluated the effectiveness of revaccination on seroprevalence. Methods: This retrospective study included 180 CCSs previously treated at Astrid Lindgren Children’s Hospital, Stockholm, between March 2019 and January 2023. Patient data were retrieved from electronic medical records. Seroprevalence data for rubella and tetanus antibodies in the 15–19-year age group were also obtained from a national seroprevalence study conducted by the Public Health Agency of Sweden. Results: CCSs exhibited significantly lower seroprevalence for both tetanus (77.7% vs. 92.7%) and rubella (79.1% vs. 97.5%) compared to age-matched controls. Revaccination with DTP-containing vaccines was more frequently administered than with the MMR vaccine. Tetanus and rubella seroprevalence were the lowest in children who had received intense chemotherapy. Among those who were revaccinated with the DTP vaccine after intensive treatment, 81 out of 98 (82.6%) had tetanus IgG levels above the threshold, compared to 24 out of 48 (50%) unvaccinated CCSs. In contrast, among those revaccinated with MMR, 57 out of 73 (78.1%) had positive rubella IgG, compared to 53 out of 73 (72.6%) unvaccinated CCSs with rubella IgG levels above the cut-off. Conclusions: Our findings highlight that vaccines are underutilized in CCSs with a notable gap in immunity, particularly among those who have undergone intensive treatments. Unexpectedly, MMR revaccination did not significantly affect rubella immunity. Given the increasing number of CCSs, it is essential to better understand how to effectively restore vaccine immunity in this population. Full article

Background: Tetanus is a vaccine-preventable disease, and therefore vaccination of women of reproductive age or during pregnancy is recommended alongside childhood tetanus vaccination. Gender-related factors related to social empowerment have been established as determinants of health service utilization; however, these social determinants have not yet been explored directly with tetanus vaccination. In response, the aim of this study was to assess overall and country-specific gender-related barriers to maternal tetanus vaccine coverage. Methods: We used data from Demographic and Health Surveys (DHS) in 39 countries implemented between 2013 and 2022. Women’s empowerment was measured through three domains of the Survey-based Women’s emPowERment index (SWPER), as well as other gender-related variables. To assess the association between measures of women’s empowerment and gender-related factors and maternal tetanus immunization coverage, we used multilevel logistic models with pooled data from the 39 countries to analyze overall patterns, and we used multivariable logistic regression for each country-specific dataset to analyze country-level associations. Results: There were notable variations in the factors associated with tetanus vaccination across countries. Overall, we observed that higher levels of women’s empowerment, as measured through social independence and decision-making autonomy using the SWPER index, were associated with higher odds of maternal tetanus protection, with adjusted odds ratios of 1.23 (95%CI: 1.10–1.37) and 1.20 (95%CI: 1.02–1.40), respectively. However, women’s empowerment related to attitude to violence was not. Higher household wealth was also associated with higher odds of maternal tetanus protection overall. Conclusions: Women’s empowerment can improve the uptake of maternal tetanus vaccine. Addressing gender-related barriers may enhance vaccination coverage and contribute to the elimination of maternal and neonatal tetanus as a public health problem. However, these barriers vary from country to country, necessitating country-specific investigations to formulate tailored recommendations. Full article

The introduction of pneumococcal conjugate vaccination (PCV) into the Argentinian Childhood National Immunization Program in 2012 marked a significant milestone in public health. Our study aims to assess the impact of this intervention on pneumococcal meningitis cases, serotype distribution, and antimicrobial resistance among pediatric populations from 2013 to 2023. Specifically, we compared the early post-PCV period (2013–2014) to the late post-PCV period (2022–2023). A total of 333 pneumococcal isolates were analyzed between 2013 and 2023. Gold standard pneumococcal serotyping was performed to identify the serotypes associated with infection in children < 6 years in Argentina, and the agar dilution method was carried out to determine their profiles to antimicrobial agents. Our findings underscore the importance of PCV implementation, revealing notable shifts in pneumococcal epidemiology over the study period. The proportions of serotypes 1 (6.7% to 0.0%), 5 (5.6% to 0.0%), and 14 (7.8% to 1.8%) decreased, whereas the proportions of serotypes 10A (3.3% to 10.7%), 15B/C (2.2% to 10.7%), and 24B (0.0% to 8.9%) increased. The top five rated serotypes in the 2022–2023 period were serogroup 24 (21.4%), 10A (10.7%), 15B/C (10.7%), 23B (7.1%), and 12F (5.4%). Regarding antimicrobial resistance, we found that a total of 115/311 isolates (37%) were not suceptible to penicillin, and 2.9% were not suceptible to cefotaxime. Twenty-five percent of the isolates were microbial drug resistant, with resistance to penicillin, erythromycin, tetracycline/doxicycline, and/or cotrimoxazol. Among the PCV13 serotypes, 19A remained the most commonly associated with MDR. The non-PCV13 serotypes, particularly 24F, 24A, and 24B, were prevalent among MDR isolates. The observed trends demonstrate the need for the continued expansion of pneumococcal vaccination policies, including consideration for vaccines offering enhanced indirect protection, thereby extending benefits beyond the pediatric population to encompass adults as well. Such strategies are pivotal in reducing the burden of pneumococcal disease and safeguarding public health. Full article

Acute gastroenteritis (AGE) has one of the highest rates of morbidity and mortality among children under five years old worldwide. It is estimated that 1.7 billion cases of childhood diarrheal diseases occur annually, leading to up to 443,832 deaths. Approximately 90% of these cases are viral, with human norovirus being the main cause in countries that have implemented rotavirus vaccines. The objective of this study was to describe the prevalence and genetic diversity of norovirus in child outpatients and inpatients under five years old at the Regional Hospital of Antofagasta. From 1 January to 31 October 2019, a total of 121 stool samples were collected to detect the presence of norovirus GI and GII using Taqman™-based real-time RT-PCR. Norovirus RNA was detected in 50 (41.3%) samples, of which 96% were typed as GII.4 Sydney (42% GII.4 Sydney[P16] and 54% GII.4 Sydney[P4 New Orleans]). Furthermore, most (92%) of the positive specimens were from children under two years of age and a majority were detected in April (38%) and May (20%). Our findings highlight the high burden of norovirus in hospitalized children with AGE and the importance of molecular strain surveillance to support vaccine development. Full article

Background: Hepatitis B virus (HBV) infection remains a significant occupational health concern for healthcare workers (HCWs), including trainees exposed to biological risks. Although vaccination is the most effective preventive measure, the persistence of immunity over time and the need for booster doses remain subjects of debate. Objective: The present study aims to assess the prevalence of protective anti-HB antibody titers among healthcare trainees at the “SS Annunziata” Hospital in Chieti, comparing those vaccinated in infancy with those vaccinated during adolescence. Methods: A retrospective observational study was conducted on 2028 healthcare trainees from 2021 to 2024. Participants were divided into two groups based on vaccination timing: infancy (PED group) and adolescence (ADO group). Serological tests were performed to measure anti-HB titers, with a protective threshold set at ≥10 IU/L. Statistical analyses were conducted to evaluate differences in immunity persistence between the two groups. The results showed that the overall prevalence of protective anti-HB titers was 50.7%, with significant differences between the PED and ADO groups. Protective immunity was observed in 79.2% of individuals vaccinated during adolescence, compared to 44.6% of those vaccinated in infancy (p < 0.001). No significant differences in antibody persistence were found between males and females. Notably, 92.4% of participants with non-protective titers received a booster dose within two months of testing. Conclusions: The study confirms a significant decline in anti-HB titers over time among individuals vaccinated in infancy, suggesting a potential need for booster doses later in adulthood. The high adherence to vaccination recommendations among healthcare trainees is a promising finding, reinforcing the importance of continuous education and immunization programmes in healthcare settings. Further research, including longitudinal studies and additional HBV biomarkers, is necessary to optimize vaccination strategies and long-term immunity monitoring in HCWs. Full article