Edina Amponsah-Dacosta

Background: Zero-dose (ZD) children, classified as those who have not received their first dose of diphtheria–tetanus–pertussis vaccine, remain at high risk of vaccine-preventable diseases globally. Despite progress, an estimated 14.3 million children were ZD in 2024. We systematically mapped global evidence on interventions to reach ZD and under-immunized children to inform policy and planning towards vaccine equity. Methods: We conducted a scoping review of peer-reviewed studies published between 2015 and 2025 reporting interventions to reach ZD or under-immunized children under five years. We searched PubMed, Scopus, Web of Science, and EBSCOhost databases. Two reviewers independently extracted data using standardized forms. We analyzed interventions thematically and by World Bank income classification. Results: Of the 37 included studies, 24% (n = 9) originated from low-income countries (LICs), 65% (n = 24) from lower-middle-income countries, 5% (n = 2) from upper-middle-income countries, and 5% (n = 2) from high-income countries. Mobile outreach programmes were the most prevalent intervention at 46% (17/37), followed by engagement with religious and community leaders at 41% (15/37) and community healthcare worker involvement at 27% (10/37). We identified eight thematic intervention areas: community engagement, community and health workforce, health systems strengthening, outreach and service delivery, technology-driven approaches, monetary incentives, integrated human–animal campaigns, and leveraging military and security forces. Intervention patterns varied by income level, with LICs emphasizing community engagement and mobile outreach, while higher-income countries utilized technology and incentive-based approaches. Five studies specifically reported on ZD children, with most reporting improvements in first dose of DTP/Penta vaccine uptake following intervention implementation. Conclusions: Multi-faceted, context-adapted interventions show promise for reaching ZD children. However, clearer definitional standards are needed to distinguish ZD from under-immunized populations. Strategies identified in this review can guide policymakers in designing and prioritizing further evaluation of interventions to achieve equity in immunization coverage globally.

Introduction: The COVID-19 pandemic has highlighted significant disparities in vaccine uptake across sub-Saharan Africa, yet research exploring the regional and country-specific factors influencing these rates remains limited. Understanding these factors is crucial for developing targeted regional and global public health interventions to improve vaccination uptake and strengthen pandemic preparedness. This study aims to fill a critical knowledge gap by assessing the factors influencing vaccination rates across sub-Saharan Africa at the operational, systemic and socio-political levels. Methods and analysis: The study will employ a comparative case study design across 12 African countries to examine context-specific factors influencing pandemic vaccine preparedness. The 12 selected countries (Angola, Botswana, Burundi, Cameroon, Côte d'Ivoire, Malawi, Namibia, Nigeria, Rwanda, Senegal, South Africa and Uganda) will be categorised by vaccination rate (high, moderate or low). The study will integrate quantitative and qualitative data to provide comprehensive insights. Quantitative data, including COVID-19, macroeconomic, health system and governance indicators, will be sourced from reputable online portals, such as the WHO, the World Bank and Our World in Data. Qualitative data will be collected through key informant interviews with experts across participating African countries, except Angola. Due to delays in obtaining ethics approval in Angola, no primary data collection including key informant interviews will be conducted in Angola unless ethics approval is obtained. Angola will therefore be included through a secondary data approach, drawing on publicly available reports, published literature and relevant case studies. All qualitative data will be analysed using thematic analysis, and quantitative data will be analysed using descriptive methods. Ethics and dissemination: Ethics approval was obtained from Western University’s Health Sciences Research Ethics Board (126398) and relevant bodies in the 11 participating countries. Findings will be shared through reports to public health authorities, policy briefs and presentations at academic conferences and peer-reviewed publications.

Respiratory Syncytial Virus (RSV) is a common cause of severe lung infections in babies, especially during their first six months of life. While RSV is a global health concern, its effects are particularly significant in countries like South Africa where access to advanced care can be limited. A new vaccine has recently been approved internationally to protect babies by vaccinating pregnant women. Although the maternal RSV vaccine is not yet available in South Africa, rollout is anticipated soon. The success of this approach relies heavily on healthcare workers (HCWs) who advise and care for pregnant women. This study aims to understand what HCWs in Cape Town know and believe about RSV and the maternal RSV vaccine, and how they feel about recommending it. This mixed-methods cross-sectional study will assess the knowledge, attitudes, and perceptions (KAP) of 230 HCWs in Cape Town, South Africa, regarding maternal RSV vaccination. Quantitative data will be collected through a structured REDCap-based survey administered on tablet devices. Semi-structured interviews will be conducted with a subset of HCWs to further explore perceived barriers, facilitators, and attitudes toward maternal RSV vaccination. Quantitative data will be analyzed using descriptive and inferential statistics in RStudio. Qualitative data will be thematically analyzed in NVivo using Braun and Clarke's framework. Findings will provide baseline evidence on HCWs' RSV-related KAP in South Africa, highlight gaps in awareness, and identify key factors influencing their support for maternal RSV vaccination. This will guide decision-makers in designing better training, communication strategies, and rollout plans for maternal vaccines. This study will guide effective maternal RSV vaccine implementation driven by a committed and capacitated health workforce.

Background: Understanding vaccine attitudes, knowledge, and perceptions is critical for improving vaccine uptake, particularly among vulnerable populations such as pregnant women. This study aimed to test and adapt quantitative survey tools and an interview guide for assessing maternal and childhood vaccine attitudes among pregnant women in the South African context. Methods: We conducted a mixed-methods pilot study among pregnant women attending antenatal care at two public hospitals in Cape Town, South Africa, between September 2023 and January 2024. Quantitative data were collected using a self-administered questionnaire on tablets, incorporating the adapted BeSD and VAX tools, while qualitative data were gathered through semi-structured interviews. Additionally, the quantitative questionnaire contained the General Vaccine Attitude Survey questions developed by the World Health Organization Strategic Advisory Group of Experts on Immunization (WHO SAGE) Working Group on Vaccine Hesitancy and a validated tool on knowledge of influenza and attitudes toward influenza vaccination during pregnancy. Adaptations to the tools were informed by participant feedback and pretesting. Results: Eighty pregnant women agreed to participate in the quantitative survey, one participant dropped out of the study and seven completed follow-up qualitative interviews. The tools were well received, with participants reporting ease of use and understanding. Minor linguistic adjustments improved clarity, and participants identified healthcare providers as key influencers in vaccine decision-making. Knowledge gaps regarding maternal vaccination and concerns about vaccine safety during pregnancy were prominent. The mixed-methods approach provided complementary insights into the tools’ applicability and participants’ attitudes. Conclusions: This pilot study demonstrated that the WHO BeSD tools, the VAX Scale, the General Vaccine Attitude Survey, and the questions on knowledge of influenza and attitudes toward influenza vaccination during pregnancy, with minor adaptations, are feasible and acceptable for use in South Africa. These findings support their application in larger studies to explore maternal vaccine confidence and decision-making. Addressing knowledge gaps and leveraging trusted sources of information is critical to enhancing vaccine uptake in similar settings.

Background: Migrant populations are commonly under-immunised relative to general populations in host countries. The evidence base on routine vaccination among migrant children suggests that higher priority is given to infants and younger children compared to adolescents. Though migrants are often classified as a homogenous group, different sub-populations of migrants exist, including voluntary migrants who choose to move and involuntary migrants forcibly displaced by humanitarian crises. The human papillomavirus (HPV) vaccine, a relatively recent addition to global routine immunisation schedules for adolescents, is a useful proxy for understanding vaccine equity for this under-prioritised group. This qualitative systematic review explores health system determinants of delivery and uptake of HPV vaccination services among involuntary migrants. Methods: A literature search was conducted across ten electronic databases. An analytical framework tailored to the migrant context aided in capturing the complexity and magnitude of systemic factors that determine vaccine delivery and uptake among involuntary migrants. Of the 676 records retrieved, 27 studies were included in this review. Results: Key determinants of vaccine delivery include adaptation of immunisation policies for migrant inclusiveness, implementation of migrant-targeted interventions, health provider recommendations, electronic health records, and free vaccines. Uptake determinants include access dependent on legal status, awareness-related determinants akin to culturally appropriate health messaging, and acceptance-related determinants associated with sociocultural beliefs, misinformation, and distrust. Conclusions: Prioritising vaccination programmes linked with non-outbreak-related diseases is challenging in the disruptive context of humanitarian crises given fragile health systems, limited resources, loss of health infrastructure and deployment of health personnel to emergency care. We strongly advocate for global actors at all health systems levels to actively reform national HPV vaccination programmes to enhance inclusivity of adolescent girls in crises settings or resettled in host countries.

Background: Migrant populations are commonly under-immunised relative to general populations in host countries. The evidence base on routine vaccination among migrant children suggests higher priority is given to infants and younger children compared to adolescents. Though migrants are often classified as a homogenous group, different sub-populations of migrants exist, including voluntary migrants who choose to move, and involuntary migrants forcibly displaced by humanitarian crises. The human papillomavirus (HPV) vaccine, a relatively recent addition to global routine immunisation schedules for adolescents, is a useful proxy for understanding vaccine equity for this under-prioritised group. This qualitative systematic review explores health system determinants of delivery and uptake of HPV vaccination services among involuntary migrants. Methods: A literature search was conducted across ten electronic databases. An analytical framework tailored to the migrant context aided in capturing the complexity and magnitude of systemic factors that determine vaccine delivery and uptake among involuntary migrants. Of the 676 records retrieved, 27 studies were included in this review. Results: Key determinants of vaccine delivery include adaptation of immunisation policies for migrant inclusiveness, implementation of migrant-targeted interventions, health provider recommendations, electronic health records and free vaccines. Uptake determinants include access dependent on legal status, awareness-related determinants akin to culturally appropriate health messaging, and acceptance-related determinants associated with sociocultural beliefs, misinformation and distrust. Conclusion: Prioritising vaccination programmes linked with non-outbreak-related diseases is challenging in the disruptive context of humanitarian crises given fragile health systems, limited resources, loss of health infrastructure and deployment of health personnel to emergency care. We strongly advocate for global actors at all health systems levels to actively reform national HPV vaccination programs to enhance inclusivity of adolescent girls in crises settings or resettled in host countries.

Introduction: Cervical cancer, which is the fourth most frequently diagnosed cancer among women globally, remains a significant health burden despite being preventable and treatable, exposing gaps in accessing prevention and control services. Adolescent girls and young women (AGYW) living with HIV face heightened risk of persistent HPV infection, a primary cause of cervical cancer, making this population the ideal target for preventing cervical cancer before HPV exposure or disease progression. The overlap of cervical cancer and HIV exacerbates public health challenges, urging intensified efforts in bolstering prevention and control measures. Integration of cervical cancer prevention strategies into HIV care programs shows promise in effectively addressing this dual burden. Methods: To evaluate the effectiveness of integrating cervical cancer prevention strategies within HIV care programs, a mixed-methods systematic review will be conducted. A comprehensive Boolean search for literature published and indexed in PubMed, Cochrane Library, EBSCO Host, Web of Science, Scopus, and Google Scholar will be conducted, without imposing any language restrictions. This review will be conducted in alignment with the Joanna Briggs guidelines on systematic reviews together with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data from eligible studies will be extracted and synthesized, and their quality assessed. Discussion: There is limited understanding of the effectiveness of integrating cervical cancer prevention and HIV care in the real-world setting. While some studies touch on integration, focus tends to be on cervical cancer screening alone, neglecting vaccination, treatment of precancerous lesions, and education programs. Previous reviews on this focus are outdated, surpassing six years. This systematic review aims to fill these evidence gaps by thoroughly evaluating the challenges and opportunities associated with integrating the full complement of HPV prevention strategies and HIV care programs. The anticipated findings could enhance service delivery models aimed at reducing cervical cancer incidence and mortality among AGYW living with HIV. Trial registration: Systematic review registration: PROSPERO registration number: CRD42024535821.

Background National Immunisation Technical Advisory Groups (NITAGs) play a critical role in evidence-informed decision-making (EIDM) for immunisation programs. However, African NITAGs face challenges, including limited technical capacity, inadequate resources, and insufficient vaccinology training tailored to their needs. To address these gaps, the NITAG Support Hub (NISH) launched the Annual Vaccinology Course for NITAGs (AVCN) in 2022. Methods The AVCN is a five-day residential course designed to enhance the technical and operational capacity of NITAGs. It combines didactic lectures, interactive sessions, and case studies to provide practical knowledge in vaccinology, health economics, and EIDM. Participants are selected in collaboration with the World Health Organisation (WHO), ensuring representation from diverse linguistic and geographic regions. Results Over three years, the AVCN trained 123 NITAG members from 19 African countries, with representation from WHO African and Eastern Mediterranean regions. Feedback collected through daily evaluations and After-Action Reviews highlights the course's relevance, comprehensive content, and practical utility. Participants emphasised the value of group training, interactive methodologies, and opportunities for experience sharing. Key improvements included increased time for discussions and expanded focus on design thinking and health systems. Conclusion The AVCN is a pioneering initiative that addresses critical gaps in NITAG capacity building in Africa. Its tailored design and iterative improvements have established it as a model for NITAG vaccinology training globally. By fostering collaboration and building technical capacity, the AVCN contributes significantly to strengthening immunisation systems in Africa and beyond.

Background: Understanding vaccine attitudes, knowledge, and perceptions is critical for improving vaccine uptake, particularly among vulnerable populations such as pregnant women. This study aimed to test and adapt the World Health Organization (WHO) Behavioural and Social Drivers (BeSD) tools and the Vaccination Attitudes Examination (VAX) Scale for assessing maternal and childhood vaccine attitudes in the South African context. Methods: We conducted a mixed-methods pilot study among pregnant women attending antenatal care at two public hospitals in Cape Town, South Africa, between September 2023 and January 2024. Quantitative data were collected using a self-administered questionnaire on tablets, incorporating the adapted BeSD and VAX tools, while qualitative data were gathered through semi-structured interviews. Additionally, the quantitative questionnaire contained the General Vaccine Attitude Survey questions developed from the compendium of survey questions created by the World Health Organization Strategic Advisory Group of Experts on Immunization (WHO SAGE) Working Group on Vaccine Hesitancy. Adaptations to the tools were informed by participant feedback and pretesting. Results: Eighty pregnant women agreed to participate in the quantitative survey, one participant dropped out of the study and seven completed follow-up qualitative interviews. The tools were well received, with participants reporting ease of use and understanding. Minor linguistic adjustments improved clarity, and participants identified healthcare providers as key influencers of vaccine decision-making. Knowledge gaps regarding maternal vaccination and concerns about vaccine safety during pregnancy were prominent. The mixed-methods approach provided complementary insights into the tools' applicability and participants' attitudes. Conclusions: This pilot study demonstrated that the WHO BeSD tools and VAX Scale, with minor adaptations, are feasible and acceptable for use in South Africa. These findings support their application in larger studies to explore maternal vaccine confidence and decision-making. Addressing knowledge gaps and leveraging trusted sources of information are critical to enhancing vaccine uptake in similar settings.

Background: There is limited evidence comparing hepatitis A seroprevalence among HIV-exposed uninfected (HEU), HIV-infected (HIV), and unexposed uninfected (HUU) children. This compromises rational vaccine decision-making. Methods: This study comprised a retrospective health facility-based population of children aged 1 month–12 years. Archival sera were tested for markers of acute (anti-HAV IgM) or past (total anti-HAV) HAV infection. Subgroup analysis was conducted based on perinatal HIV exposure or infection status. Results: Among 513 children, the median age was 10 (IQR: 4–25) months. The median maternal age was 29 (IQR: 25–34) years. An anti-HAV seropositivity of 95.1% (117/122 [95% CI 90.2–98.4]) was found among those ≤6 months of age, indicative of the rate of transplacental antibody transfer. Among 1–12-year-olds, hepatitis A seroprevalence was 19.3% (37/192 [95% CI 14.1–25.7]), while 1.1% (2/188 [95% CI 0.12–2.76]) had evidence of acute infection. Compared to HIV-exposed subgroups (HIV = 60%, 6/10 [95% CI 27.4–86.3] and HEU = 45%, 9/20 [95% CI 23.8–68]), hepatitis A seroprevalence among HUU children was low (29.2%, 47/161 [95% CI 22.4–37.0]). Conclusions: Natural immunity among HIV-exposed and unexposed children in South Africa is insufficient to protect against severe liver complications associated with HAV infection later in adulthood.