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22,944 reports · page 758 of 2295

Peer-reviewed articlePubMed (US National Library of Medicine)13 May 2026

Seroprevalence and predictors of measles antibody positivity among children aged 18-24 months in Pakistan: a national survey.

BACKGROUND: Measles remain a leading cause of childhood morbidity and mortality. Despite improved vaccine coverage, the number of laboratory-confirmed measles cases in Pakistan doubled between 2019 and 2020. Although an effective vaccine has been available for decades, sporadic outbreaks continue to occur. This study aimed to determine the seroprevalence of measles IgG antibodies among vaccinated children in Pakistan. METHODS: A cross-sectional survey was conducted between April 2019 and October 2020 in seven districts across Pakistan. Using a multistage sampling technique, healthy children aged 18-24 months with a history of measles vaccination were randomly enrolled after obtaining informed written consent. Venous blood samples (3 cc) were collected and tested for measles IgG antibodies using ELISA. RESULTS: Among 3596 vaccinated children, 65% were seropositive for measles IgG antibodies. Vaccine coverage was high, with 90% receiving the first measles dose (MCV1) administered at 9 months of age and 78% the second dose (MCV2) administered at 15 months. Seropositivity was significantly associated with vaccination source, documentation status, rural residence, place of delivery, and history of prior measles infection. Higher seroprevalence was observed among children vaccinated by mobile vaccinators compared to other vaccination settings. CONCLUSION: Seroconversion among vaccinated children was suboptimal, with only 65% achieving protective antibody levels. The first dose of measles vaccine appeared particularly important for antibody development. Strengthening vaccination services, ensuring delivery through trained vaccinators, and conducting regular seroprevalence surveys are essential for evidence-based policies to achieve measles elimination in Pakistan.

Najma Javed, Maimoona Sabir, Mohammad Arif Nadeem Saqib et al.

Peer-reviewed articlePubMed (US National Library of Medicine)15 May 2026

Dropout from the pentavalent vaccine series among children aged 12-23 months in the Central African Republic: prevalence, associated factors, and caregiver-reported barriers.

BACKGROUND: Routine childhood immunization in the Central African Republic (CAR) is inconsistent due to reasons including political instability and service disruptions. This study assessed dropout between the first and third pentavalent doses among children aged 12-23 months who had received Penta 1, identified associated risk factors, and explored caregiver-reported barriers. Additional dropout indicators within this cohort-specifically from Penta 1 to Penta2, from Penta2 to Penta 3, and from Penta 3 to measles-were also examined to support contextual interpretation. METHODS: We conducted a cross-sectional household survey from December 2023 to March 2024, based on a nationally representative sample covering all seven health regions and 35 districts of the CAR. This secondary analysis focused on dropout between key vaccine doses among children aged 12-23 months and was conducted using Stata 17. Data were collected through structured interviews with caregivers, with vaccination status primarily verified using home-based records; when unavailable, health facility data or caregiver recall were used. Survey-weighted logistic regression models were used to identify factors associated with vaccine dropout. Reasons for non-vaccination were analyzed thematically using the adapted WHO BeSD framework. RESULTS: Among 4121 children aged 12-23 months who had received Penta 1, the national prevalence of dropout between the first and third doses of the pentavalent vaccine was 34.5% (95% CI: 32.4-36.6). Additionally, among these children, we observed 17.0% dropout from Penta 1 to Penta2, 17.5% from Penta2 to Penta 3, and 15.8% from Penta 3 to the measles-containing vaccine. Higher odds of dropout between Penta 1 and Penta 3 were associated with households lacking television (aOR: 2.98; 95% CI:1.88-4.72), absence of birth registration (aOR:1.56; 95% CI:1.26-1.94) and caregivers engaged in agricultural activities (aOR:3.45; 95% CI:1.85-6.44). Primary reported reasons for non-vaccination included access barriers such as distance to the vaccination site (30.9%) and vaccine stockouts (14.0%), contextual and household challenges like caregiver time constraints (29.7%) and family-related problems (10.8%), information gaps including lack of knowledge about the vaccination schedule (27.3%), and motivational concerns such as fear of side effects (10.4%) and distrust in vaccines (2.9%). CONCLUSION: In the CAR, 34.5% of children who receive the first pentavalent dose fail to complete the three dose vaccination series. Improving follow-up and adapting services to overcome local barriers is essential to increase rates of complete immunization.

Daniel Katuashi Ishoso, Emmanuel Fandema, Nicole A Hoff et al.

SurvivalPre/postCFRead at source

Peer-reviewed articlePubMed (US National Library of Medicine)15 May 2026

Instruments for measuring parents' vaccine hesitancy towards their children based on the COSMIN guidelines: A systematic review.

BACKGROUND: Parental vaccine hesitancy undermines immunization gains, leading to resurgent outbreaks and increased child mortality. Reliable assessment instruments are urgently needed to guide effective interventions and improve coverage. Despite multiple vaccine hesitancy assessment instruments, no systematic reviews have evaluated the measurement properties of these instruments against established methodological standards, limiting evidence-based selection. OBJECTIVE: To systematically evaluate the methodological quality and measurement properties of vaccine hesitancy assessment instruments for parents of 0-18 children, providing an evidence-based basis for selecting appropriate instruments. DESIGN: Measurement properties are systematically reviewed according to the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines. METHODS: Six electronic databases were systematically searched from inception until July 15, 2025. Methodological quality was assessed using the COSMIN Risk of Bias Checklist and measurement properties were synthesized according to the COSMIN criteria. A modified Grading, Recommendations, Assessment, Development, and Evaluation system was used to assess the certainty of evidence. RESULTS: Forty studies evaluating 31 vaccine hesitancy assessment instruments were included. Based on COSMIN evidence grading, the Malay version of the modified vaccine hesitancy scale (MVHS-M), the Vietnamese version of the parent attitudes about childhood vaccines survey (PACV-Viet), and the parental attitude scale towards vaccination (PASV) received Category A recommendation. The general vaccine hesitancy scale (GVHS), vaccination attitudes examination (VAX), vaccine acceptance instrument (VAI), and vaccine barriers assessment tool (VBAT) received Category C recommendation, while others were Category B recommendation. CONCLUSIONS: This systematic review identified MVHS-M, PACV-Viet, and PASV as effective tools for assessing vaccine hesitancy in parents, suitable for both research and clinical use. Future research should comprehensively assess their measurement properties, especially exploring measurement error and responsiveness. REGISTRATION: A protocol was registered on the PROSPERO (CRD420251070194).

Ting Cao, Bin Chen, Shi Chen et al.

SurvivalRead at source

Peer-reviewed articlePubMed (US National Library of Medicine)19 May 2026

Racial disparities in coverage and determinants of childhood diphtheria, tetanus, and pertussis (DTaP) vaccination in Canada: a post-COVID-19 pandemic analysis.

Vaccination is essential for preventing infectious diseases, yet childhood vaccine uptake declined in Canada following the COVID-19 pandemic, raising concerns amid the resurgence of pertussis. This study aimed to assess coverage and determinants of diphtheria, tetanus, and pertussis (DTaP) vaccination among children in Canada in the post-COVID-19 context. We analyzed data from a national survey of Canadian parents of children aged 0-12 years (N = 2528), with oversampling of Arab, Asian, Black, and Indigenous groups to enable accurate racial comparisons. Sociodemographic characteristics, health literacy, and vaccine-related conspiracy beliefs were evaluated. Overall vaccination coverage was 73% for diphtheria, 74% for pertussis, and 77% for tetanus. Significant racial disparities were observed across all outcomes (p < .001), with lower uptake among children of Arab, Asian, Black, and Indigenous parents compared with children of White parents. Vaccination varied significantly across provinces. After adjusting for sociodemographic factors, higher endorsement of vaccine-related conspiracy beliefs was associated with reduced odds of vaccination across all outcomes (diphtheria: aOR = 0.79, 95%CI: 0.72-0.87; tetanus: aOR = 0.70, 95%CI: 0.63-0.77; pertussis: aOR = 0.71, 95%CI: 0.64-0.78), whereas higher health literacy was associated with increased uptake (diphtheria: aOR = 1.37, 95%CI: 1.25-1.50; tetanus: aOR = 1.22, 95%CI: 1.11-1.34; pertussis: aOR = 1.26, 95%CI: 1.15-1.38). These findings demonstrate persistent racial inequities in childhood DTaP vaccination in Canada post-pandemic, shaped by structural and health behaviors' determinants. Targeted, culturally responsive strategies addressing misinformation and improving health literacy are critical to restoring vaccine coverage and preventing future outbreaks.

Rose Darly Dalexis, Idrissa Beogo, Taddele Cherinet Kibret et al.

SurvivalCARead at source

Peer-reviewed articlePubMed (US National Library of Medicine)14 Jul 2026

Assessing vaccination coverage quality in Jamaica during COVID-19 using vcqiR: insights from the 2022 MICS.

OBJECTIVE: This analysis aimed to identify the underlying causes of gaps in routine immunization coverage observed during the COVID-19 pandemic recovery phase by applying the open-source Vaccination Coverage Quality Indicators package in R (vcqiR), addressing limitations in Multiple Indicator Cluster Surveys (MICS) that often omit quality metrics based on detailed vaccination date analysis. METHODS: This secondary analysis examined vaccination doses and dates from the Jamaica 2022 MICS (MICS4), for 570 children ages 12-23 months and 24-35 months. Specific indicators included coverage, timeliness, dropouts, and missed opportunities for simultaneous vaccinations (MOSVs). RESULTS: Vaccination coverage for first-year-of-life (1YL) doses exceeded 83% for both age cohorts. Coverage for MMR1 showed substantial catch-up from 12-23 months to 24-35 months, achieving the 95% target. However, MMR2 coverage lagged substantially (37.2% for 12-23 months and 61.9% for 24-35 months), indicating significant attrition in the second year of life. In the 12-23 month cohort, crude coverage of Penta3 was 89%, but only 70% had three valid doses. Most 1YL doses were administered in a timely manner (within 28 days), but premature administration was observed. MOSVs were negligible for 1YL doses but were frequent and mostly uncorrected for 18-month boosters, especially MMR2. CONCLUSIONS: The findings complement the MICS4 report and confirm robust early infant immunization delivery but identify programmatic gaps in second year-of-life retention plus the need to strengthen adherence to minimum age interval rules. These results provide detailed evidence necessary to inform targeted interventions and guide the design of future coverage surveys.

Anya Cushnie, Dale A Rhoda, Caitlin B Clary et al.

SurvivalPractitionerJMRead at source

Peer-reviewed articlePubMed (US National Library of Medicine)17 Jul 2026

Response to a vaccine-derived poliovirus type 1 event - Sichuan, China, 2024.

BACKGROUND: In September 2024, a 4-month-old infant in Liangshan, Sichuan, China was diagnosed with paralytic poliomyelitis that turned out to have been caused by a vaccine-derived poliovirus type 1 (VDPV1). This was the third VDPV outbreak detected by routine acute flaccid paralysis (AFP) surveillance in Sichuan since 2012. We conducted an epidemiological investigation into the event and implemented response measures to prevent further viral spread. METHODS: The investigation and response were conducted according to World Health Organization (WHO) and China's National Health Commission standard operating procedures. Measures included case and virus verification; search for poliovirus among contacts, healthy children, and in wastewater; active surveillance for AFP cases in health facilities and communities; vaccination coverage assessment; and supplementary immunization activity (SIA) and catch-up vaccination. RESULTS: The paralyzed infant was determined to be a VDPV1 case by the Sichuan provincial expert group; the VDPV1 had 10-15 nucleotide changes from Sabin strain type 1. No VDPVs were found in close contacts, healthy children, or wastewater; no AFP cases were found in health facilities or communities; no local circulation of the VDPV1 was detected. Following a county-wide SIA with catch-up vaccination, 2-dose, bivalent live attenuated polio vaccine coverage was 95.4% among children four months to four years of age, and full-series polio vaccine coverage was 98.5% in children 5-14 years of age. CONCLUSIONS: The VDPV was an ambiguous VDPV type 1 (aVDPV1). Timely detection and response prevented further spread and development of a circulating VDPV type 1 (cVDPV1). Low vaccination coverage and poor sanitation were contributing factors to the emergence of the aVDPV1. Information technology facilitated the strategy of "Government Locates, Health Vaccinates" that rapidly raised population immunity in a low-coverage area through a high-quality SIA and interrupted spread of the virus. CLINICAL TRIAL NUMBER: Not applicable.

Qing Yang, Jiajie Liu, Yi Liu et al.

SurvivalCNRead at source

Peer-reviewed articlePubMed (US National Library of Medicine)17 Jul 2026

Using mobile phone Re-call notification as a primary care practice to improve vaccination uptake for children under five in baghdad, Iraq, 2022.

INTRODUCTION: Reminder and recall (RR) interventions are proven strategies for improving childhood immunization coverage. However, evidence on their feasibility and effectiveness in routine primary healthcare settings in Iraq is limited. This study evaluated a direct, person-to-person mobile phone recall intervention to improve vaccine uptake among children under five years of age in Baghdad Province in 2022. METHODS: The intervention was implemented in 50 Primary Healthcare Centers (PHCs) with the lowest routine immunization performance, including 20 centers in Karkh and 30 in Rusafa. Eligible participants were children under five years of age who were overdue for one or more vaccines in the national Expanded Programme on Immunization (EPI) schedule, excluding Bacillus Calmette-Guérin (BCG) vaccine administered at birth. Trained EPI staff contacted caregivers through direct telephone calls, with up to six biweekly attempts over a three-month period. Standardized data collection forms were used under supervision of the Directorate of Public Health. RESULTS: A total of 17,241 children (47.8% female) with 48,919 overdue vaccine doses were identified, of whom 15,087 (87.4%) had valid mobile phone numbers. Among these, 28,130 call attempts resulted in 10,061 caregiver responses. Most respondents (87.5%) agreed to schedule vaccination appointments. Ultimately, 6,831 children attended PHCs and received 13,386 overdue vaccine doses, corresponding to 39.4% child-level and 27.4% dose-level coverage among targeted defaulters. CONCLUSION: Direct cellphone-based recall interventions are feasible and operationally effective for improving routine childhood immunization in Iraq. As a low-cost strategy embedded within existing EPI structures, this approach has strong potential for scale-up in similar settings.

Firas Jabbar, Kamal A Kadhim, Riyadh A Alhilfi et al.

SurvivalPractitionerIQRead at source

Peer-reviewed articlePubMed (US National Library of Medicine)18 Jul 2026

Ten-year epidemiological and clinical insights of pediatric influenza A and B hospitalizations: an observational study.

Infants and children under 5 years of age face a high risk of severe complications, including pneumonia and neurologic issues, from influenza virus infection. Hospital surveillance data can provide guidance for immunization recommendation policies to prevent severe influenza complications in the pediatric population. The aim of this study was to investigate the factors associated with influenza virus type and subtype in children and adolescents hospitalized with laboratory-confirmed influenza and compare the results obtained in previous analyses from 2010/11 to 2015/16 (P1) and 2016/17 to 2019/20 (P2). We carried out a retrospective descriptive study during ten influenza seasons (2010-2011 to 2019-2020) on laboratory-confirmed influenza in cases aged 0-17 years hospitalized for severe acute influenza virus infection (SHLCI). A total of 528 pediatric hospitalizations with laboratory-confirmed influenza were reported, 274 (51.9%) were male and 285 (54.0%) were aged 1-4 years. One hundred and two patients (19.3%) required ICU admission; 112 (21.2%) had preexisting comorbidities. The median length of stay was 5 days (range: 1-129). The main complications were pneumonia (61.8%), ARDS (29.7%) and 4 deaths. There was no significant difference in the incidence of complications according to virus type. The distribution according to influenza virus type and subtype was as follows: 79.4% had influenza A (43.7% H1N1pdm09, 14.1% H3N2), and 20.6% had influenza B. Only 5.4% had received the seasonal influenza vaccine. Our results confirm that, among the pediatric population, severe influenza predominantly affects younger children, who are often previously healthy, and is associated with substantial complications and ICU burden. The low degree of vaccination coverage among hospitalized children emphasizes the need to improve influenza immunization strategies in pediatric populations.

Mireia Jané, Núria Soldevila, Núria Torner et al.

SurvivalRead at source

Every report we find, newest first.

How to use the reports

Seroprevalence and predictors of measles antibody positivity among children aged 18-24 months in Pakistan: a national survey.

Dropout from the pentavalent vaccine series among children aged 12-23 months in the Central African Republic: prevalence, associated factors, and caregiver-reported barriers.

Instruments for measuring parents' vaccine hesitancy towards their children based on the COSMIN guidelines: A systematic review.

Racial disparities in coverage and determinants of childhood diphtheria, tetanus, and pertussis (DTaP) vaccination in Canada: a post-COVID-19 pandemic analysis.

Vaccination Coverage Quality Indicators (VCQI): a flexible open-source tool for survey data analysis.

Assessing vaccination coverage quality in Jamaica during COVID-19 using vcqiR: insights from the 2022 MICS.

Response to a vaccine-derived poliovirus type 1 event - Sichuan, China, 2024.

National expert consensus recommendations on influenza vaccination in Saudi Arabia (2025).

Using mobile phone Re-call notification as a primary care practice to improve vaccination uptake for children under five in baghdad, Iraq, 2022.

Ten-year epidemiological and clinical insights of pediatric influenza A and B hospitalizations: an observational study.

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