Trial reportClinical infectious diseases : an official publication of the Infectious Diseases Society of America2020
Increase of Dose Associated With Decrease in Protection Against Controlled Human Malaria Infection by PfSPZ Vaccine in Tanzanian Adults.
Trial report in Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 2 registered trials, which are not on this map. Cited by 45 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.
Clinical Trial to Evaluate the Safety and Immunogenicity in Age De-Escalation of Direct Venous Inoculation of a Plasmodium Falciparum Sporozoite Vaccine in Tanzanian Adults, Children, and Infants
Randomized, Placebo-Controlled, Double-Blind Study to Assess Safety, Immunogenicity, and Protective Efficacy of Two Regimens of Radiation Attenuated Plasmodium Falciparum NF54 Sporozoites (PfSPZ Vaccine) During Natural Transmission Season in Healthy African Adults in Mali
Who cites it
45 citing papers in PubMed, 1 synthesis or guideline pooled it, 71 citations in OpenAlex.
- Pooled it
- Safety, tolerability and immunogenicity of a condensed, multi-dose prime regimen of PfSPZ Vaccine for the prevention of Plasmodium falciparum malaria infection.Malaria journal · 2025Trial
- Innate immune activation restricts priming and protective efficacy of the radiation-attenuated PfSPZ malaria vaccine.JCI insight · 2024Trial
- Safety and protective efficacy of PfSPZ Vaccine administered to HIV-negative and -positive Tanzanian adults.The Journal of clinical investigation · 2024Trial
- Safety and Immunogenicity of Radiation-Attenuated PfSPZ Vaccine in Equatoguinean Infants, Children, and Adults.The American journal of tropical medicine and hygiene · 2023Trial
- A randomized controlled trial showing safety and efficacy of a whole sporozoite vaccine against endemic malaria.Science translational medicine · 2022Trial
- Randomized clinical trial to assess the protective efficacy of a Plasmodium vivax CS synthetic vaccine.Nature communications · 2022Trial
- Trial
- Repeat controlled human malaria infection of healthy UK adults with blood-stageFrontiers in immunology · 2022Trial
- Optimal control and cost-effectiveness analysis of PfSPZ vaccination and indoor residual spraying in malaria transmission: a case study in Keerom.Frontiers in public health · 2026Article
- The path from early- to late-liver stage arresting genetically attenuated parasites as a malaria vaccination strategy.NPJ vaccines · 2025Review
- Assessment of Health Status and Creation of a Registry of Potential Research Participants Aged 1.5 to 50 Years on Bioko Island, Equatorial Guinea.The American journal of tropical medicine and hygiene · 2025Article
- Malaria Vaccines and Global Equity: A Scoping Review of Current Progress and Future Directions.Biomedicines · 2025Review
- Long lived liver-resident memory T cells of biased specificities for abundant sporozoite antigens drive malaria protection by radiation-attenuated sporozoite vaccination.PLoS pathogens · 2025Article
- Controlled human malaria infection: overview and potential application in the evaluation of transmission-blocking interventions in malaria-endemic areas.Malaria journal · 2025Review
- A conserved Plasmodium nuclear protein is critical for late liver stage development.Communications biology · 2024Article
- Malaria vaccine efficacy, safety, and community perception in Africa: a scoping review of recent empirical studies.Infection · 2024Article
- Whole-sporozoite malaria vaccines: where we are, where we are going.EMBO molecular medicine · 2024Review
- PfSPZ Vaccine induces focused humoral immune response in HIV positive and negative Tanzanian adults.EBioMedicine · 2024Article
- Piloting delivery of PfSPZ vaccines for malaria through a cryogenic vaccine cold chain to travel and military medicine clinics.Journal of travel medicine · 2024Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
33 authors at 7 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundA vaccine would be an ideal tool for reducing malaria's impact. PfSPZ Vaccine (radiation attenuated, aseptic, purified, cryopreserved Plasmodium falciparum [Pf] sporozoites [SPZ]) has been well tolerated and safe in >1526 malaria-naive and experienced 6-month to 65-year-olds in the United States, Europe, and Africa. When vaccine efficacy (VE) of 5 doses of 2.7 × 105 PfSPZ of PfSPZ Vaccine was assessed in adults against controlled human malaria infection (CHMI) in the United States and Tanzania and intense field transmission of heterogeneous Pf in Mali, Tanzanians had the lowest VE (20%).
methodsTo increase VE in Tanzania, we increased PfSPZ/dose (9 × 105 or 1.8 × 106) and decreased numbers of doses to 3 at 8-week intervals in a double blind, placebo-controlled trial.
resultsAll 22 CHMIs in controls resulted in parasitemia by quantitative polymerase chain reaction. For the 9 × 105 PfSPZ group, VE was 100% (5/5) at 3 or 11 weeks (P < .000l, Barnard test, 2-tailed). For 1.8 × 106 PfSPZ, VE was 33% (2/6) at 7.5 weeks (P = .028). VE of dosage groups (100% vs 33%) was significantly different (P = .022). Volunteers underwent repeat CHMI at 37-40 weeks after last dose. 6/6 and 5/6 volunteers developed parasitemia, but time to first parasitemia was significantly longer than controls in the 9 × 105 PfSPZ group (10.89 vs 7.80 days) (P = .039), indicating a significant reduction in parasites in the liver. Antibody and T-cell responses were higher in the 1.8 × 106 PfSPZ group.
conclusionsIn Tanzania, increasing the dose from 2.7 × 105 to 9 × 105 PfSPZ increased VE from 20% to 100%, but increasing to 1.8 × 106 PfSPZ significantly reduced VE. CLINICAL TRIALS REGISTRATION: NCT02613520.
Indexed as
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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.