ArticleBMJ open2021
Population differences in vaccine responses (POPVAC): scientific rationale and cross-cutting analyses for three linked, randomised controlled trials assessing the role, reversibility and mediators of immunomodulation by chronic infections in the tropics.
Article in BMJ open, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
13 citing papers in PubMed.
- Cohort profile: the Entebbe Mother and Baby Study (EMaBS).BMJ open · 2026Trial
- The effect of intermittent preventive treatment for malaria with dihydroartemisinin-piperaquine on vaccine-specific responses among schoolchildren in rural Uganda (POPVAC B): a double-blind, randomised controlled trial.The Lancet. Global health · 2024Trial
- The effect of intensive praziquantel administration on vaccine-specific responses among schoolchildren in Ugandan schistosomiasis-endemic islands (POPVAC A): an open-label, randomised controlled trial.The Lancet. Global health · 2024Trial
- Schistosome and malaria exposure and urban-rural differences in vaccine responses in Uganda: a causal mediation analysis using data from three linked randomised controlled trials.The Lancet. Global health · 2024Trial
- The effect of BCG revaccination on the response to unrelated vaccines in urban Ugandan adolescents (POPVAC C): an open-label, randomised controlled trial.The Lancet. Global health · 2024Trial
- Rural-urban differences in oral typhoid vaccine responses in Uganda: contribution of Schistosoma mansoni.NPJ vaccines · 2026Article
- Global disparities in the introduction, scale-up, and effectiveness evaluation of COVID-19 vaccines.Nature communications · 2025Article
- A phase I COVID-19 vaccine trial among SARS-CoV-2 seronegative and seropositive individuals in Uganda utilizing a self-amplifying RNA vaccine platform: Screening and enrollment experiences.Human vaccines & immunotherapeutics · 2023Article
- Schistosoma mansoni infection alters the host pre-vaccination environment resulting in blunted Hepatitis B vaccination immune responses.PLoS neglected tropical diseases · 2023Article
- NIHR Global Health Research Group on Vaccines for vulnerable people in Africa (VAnguard): Concept and Launch event report.NIHR open research · 2023Article
- Schistosoma mansoni infection induces plasmablast and plasma cell death in the bone marrow and accelerates the decline of host vaccine responses.PLoS pathogens · 2022Article
- Characterising co-infections with Plasmodium spp., Mansonella perstans or Loa loa in asymptomatic children, adults and elderly people living on Bioko Island using nucleic acids extracted from malaria rapid diagnostic tests.PLoS neglected tropical diseases · 2022Article
- Chronic Immune Activation and CD4Frontiers in immunology · 2021Review
Corrections and comments
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Authors and funding
17 authors.
Funding
Abstract
introductionVaccine-specific immune responses vary between populations and are often impaired in low income, rural settings. Drivers of these differences are not fully elucidated, hampering identification of strategies for optimising vaccine effectiveness. We hypothesise that urban-rural (and regional and international) differences in vaccine responses are mediated to an important extent by differential exposure to chronic infections, particularly parasitic infections. METHODS AND ANALYSIS: Three related trials sharing core elements of study design and procedures (allowing comparison of outcomes across the trials) will test the effects of (1) individually randomised intervention against schistosomiasis (trial A) and malaria (trial B), and (2) Bacillus Calmette-Guérin (BCG) revaccination (trial C), on a common set of vaccine responses. We will enrol adolescents from Ugandan schools in rural high-schistosomiasis (trial A) and rural high-malaria (trial B) settings and from an established urban birth cohort (trial C). All participants will receive BCG on day '0'; yellow fever, oral typhoid and human papilloma virus (HPV) vaccines at week 4; and HPV and tetanus/diphtheria booster vaccine at week 28. Primary outcomes are BCG-specific IFN-γ responses (8 weeks after BCG) and for other vaccines, antibody responses to key vaccine antigens at 4 weeks after immunisation. Secondary analyses will determine effects of interventions on correlates of protective immunity, vaccine response waning, priming versus boosting immunisations, and parasite infection status and intensity. Overarching analyses will compare outcomes between the three trial settings. Sample archives will offer opportunities for exploratory evaluation of the role of immunological and 'trans-kingdom' mediators in parasite modulation of vaccine-specific responses. ETHICS AND DISSEMINATION: Ethics approval has been obtained from relevant Ugandan and UK ethics committees. Results will be shared with Uganda Ministry of Health, relevant district councils, community leaders and study participants. Further dissemination will be done through conference proceedings and publications. TRIAL REGISTRATION NUMBERS: ISRCTN60517191, ISRCTN62041885, ISRCTN10482904.
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