Trial reportPloS one2015
Heterologous Protection against Malaria after Immunization with Plasmodium falciparum Sporozoites.
Trial report in PloS one, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT01660854 (Re-exposure of Previously Immunized and Challenged Human Volunteers to a Heterologous Strain of P. Falciparum Sporozoites), which is not on this map. Cited by 33 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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.
Re-exposure of Previously Immunized and Challenged Human Volunteers to a Heterologous Strain of P. Falciparum Sporozoites
Who cites it
33 citing papers in PubMed, 1 synthesis or guideline pooled it, 54 citations in OpenAlex.
- Reproducibility of malaria sporozoite challenge model in humans for evaluating efficacy of vaccines and drugs: a systematic review.BMC infectious diseases · 2021Pooled it
- Trial
- Heterologous protection against malaria by a simple chemoattenuated PfSPZ vaccine regimen in a randomized trial.Nature communications · 2021Trial
- Outcomes of controlled human malaria infection after BCG vaccination.Nature communications · 2019Trial
- Modest heterologous protection after Plasmodium falciparum sporozoite immunization: a double-blind randomized controlled clinical trial.BMC medicine · 2017Trial
- Trial
- The endemic dilemma: why whole sporozoite malaria vaccine efficacy falls in the field.Trends in parasitology · 2026Review
- Controlled Human Malaria Infection Studies in Africa-Past, Present, and Future.Current topics in microbiology and immunology · 2024Review
- Plasmodium falciparum 7G8 challenge provides conservative prediction of efficacy of PfNF54-based PfSPZ Vaccine in Africa.Nature communications · 2022Article
- Five decades of clinical assessment of whole-sporozoite malaria vaccines.Frontiers in immunology · 2022Review
- A portfolio of geographically distinct laboratory-adapted Plasmodium falciparum clones with consistent infection rates in Anopheles mosquitoes.Malaria journal · 2021Article
- Strains used in whole organism Plasmodium falciparum vaccine trials differ in genome structure, sequence, and immunogenic potential.Genome medicine · 2020Article
- Fast and fierce versus slow and smooth: Heterogeneity in immune responses to Plasmodium in the controlled human malaria infection model.Immunological reviews · 2020Review
- Malaria vaccines: facing unknowns.F1000Research · 2020Review
- Beyond Blood Smears: Qualification ofThe American journal of tropical medicine and hygiene · 2019Article
- Vaccination With Sporozoites: Models and Correlates of Protection.Frontiers in immunology · 2019Review
- Malaria prevention: from immunological concepts to effective vaccines and protective antibodies.Nature immunology · 2018Review
- A Specific PfEMP1 Is Expressed in P. falciparum Sporozoites and Plays a Role in Hepatocyte Infection.Cell reports · 2018Article
- A Macrophage Colony-Stimulating-Factor-Producing γδ T Cell Subset Prevents Malarial Parasitemic Recurrence.Immunity · 2018Article
- Protection from experimental cerebral malaria with a single intravenous or subcutaneous whole-parasite immunization.Scientific reports · 2018Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
11 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundSterile protection in >90% of volunteers against homologous Plasmodium falciparum infection has been achieved only using the controlled human malaria infection (CHMI) model. This efficient model involves whole parasite immunizations under chloroquine prophylaxis (CPS-immunization), requiring only 30-45 mosquitoes bites infected with P. falciparum-sporozoites. Given the large diversity of P. falciparum parasites, it is essential to assess protection against heterologous parasite strains.
methodsIn an open-label follow-up study, 16 volunteers previously CPS-immunized and challenged with P. falciparum NF54 (West-Africa) in a dose de-escalation and challenge trial were re-challenged with clone NF135.C10 (Cambodia) at 14 months after the last immunization (NCT01660854).
resultsTwo out of thirteen NF54 protected volunteers previously fully protected against NF54 were also fully protected against NF135.C10, while 11/13 showed a delayed patency (median prepatent period of 10.5 days (range 9.0-15.5) versus 8.5 days in 5 malaria-naïve controls (p = 0.0005). Analysis of patency by qPCR indicated a 91 to >99% estimated reduction of liver parasite load in 7/11 partially protected subjects. Three volunteers previously not protected against NF54, were also not protected against NF135.C10.
conclusionThis study shows that CPS-immunization can induce heterologous protection for a period of more than one year, which is a further impetus for clinical development of whole parasite vaccines.
trial registrationClinicaltrials.gov NCT01660854.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.