RTS,S/AS01B
BiologicalEach RTS,S/AS01B dose will be given intramuscularly, and will contain 50mcg of RTS,S and standard adult dose of AS01
NCT Number: NCT01883609
This is a clinical trial in which healthy volunteers will be administered experimental malaria vaccines. One group of volunteers will receive vaccination with the leading malaria vaccine candidate, RTS,S/AS01. This vaccine schedule will consist of 3 doses of RTS,S/AS01 with an interval of 4 weeks between doses (Doses given at 0,4 and 8 week timepoints). Another group will receive a vaccination schedule composed of the same dosage and timing regimen of RTS,S, but they will also receive vaccination with ChAd63 ME-TRAP, 2 weeks after the first RTS,S followed 8 weeks later by vaccination with MVA ME-TRAP (2 and 10 week timepoints).
The study will assess the safety of the vaccinations, and the immune responses to vaccination. Immune responses are measured by tests on blood samples. Volunteers will be infected with malaria by mosquito bites, 12 weeks after the first vaccination. In addition, a group of volunteers not receiving vaccines will also be infected with malaria by the same method. These infection experiments will be used to assess vaccine efficacy: how well the vaccines act to prevent malaria disease. A further single volunteer may also be infected with malaria; this volunteer participated in a previous trial where they received vaccines and was completely protected against malaria disease after infection by mosquito bite.
The RTS,S/AS01 vaccine is a protein (RTS,S) mixed with an adjuvant (AS01). The ChAd63 ME-TRAP and MVA ME-TRAP vaccines are called viral vectored vaccines. They are made from viruses which are modified so that they can not multiply. The viruses have extra DNA in them so that after injection, the body makes malaria proteins (but malaria does not develop), so that the immune system builds a response to malaria without having been infected by it.
Healthy volunteers will be recruited in England at three research sites: in Oxford, London and Southampton.
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Notify Me18 year–45 year
All sexes
Interventional
Phase 1 / Phase 2
Wellcome Trust CRF, Southampton General Hospital, University of Southampton, Southampton, Hampshire, United Kingdom
Healthy volunteers accepted: Yes
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
The volunteer must satisfy all the following criteria to be eligible for the study:
Exclusion criteria
The volunteer may not enter the study if any of the following apply:
Each RTS,S/AS01B dose will be given intramuscularly, and will contain 50mcg of RTS,S and standard adult dose of AS01
ChAd63 ME-TRAP will be given intramuscularly at a dose of 5 x 1010 vp
MVA ME-TRAP will be given intramuscularly at a dose of 2 x 108 pfu
Time frame: 12 months
Use statistical analysis to compare number of completely protected individuals (those who do not, by Day 21 following sporozoite challenge, develop blood stage infection measured by occurrence of P. falciparum parasitemia, assessed by blood slide).
Time frame: 12 months
Occurrence of solicited and unsolicited adverse events will be monitored at each clinic visit (from diary cards, clinical review, clinical examination (including observations) and laboratory results).
Time frame: 12 months
Exploratory analysis of the correlation of the following humoral and cellular immune responses with vaccine efficacy: Anti-CS (RT, C-term, full-length), anti-HBs, and anti-ME-TRAP antibody titers; frequency of CS-specific, HBs-specific, and TRAP and ME specific T cells; ChAd63 neutralizing antibody titers. Exploratory analysis of transcriptomic correlates of vaccine immunogenicity and efficacy (this may be undertaken by microarray analysis or RNA sequencing or both techniques).
Time frame: 12 months
Separate analyses on the following endpoints: (i) blood stage malaria infection as defined by 20 or more P. falciparum parasites/ml in peripheral blood by quantitative PCR, (ii) blood stage infection as defined by 500 or more parasites/ml in peripheral blood by quantitative PCR, and (iii) blood stage infection defined by a composite of symptoms, blood film result and parasitaemia. Parasite density dynamics and parasite multiplication rates will also be compared.
Time frame: 12 months
Long term efficacy of the Group 1 and Group 2 vaccination regimens will be assessed by re-challenging any sterilely protected individuals at 5 - 7 months after the first CHMI and comparing the number of re-challengees who develop blood stage infection, and the time between CHMI and blood stage infection, with unvaccinated controls. Long term efficacy of ChAd63-MVA CS heterologous prime-boost immunisation will be assessed by rechallenging the sterilely protected volunteer from the VAC045 clinical trial and comparing the protection against blood stage infection or time between CHMI and blood stage infection, with unvaccinated controls.
University of Oxford
Other
A Phase I/IIa Sporozoite Challenge Study to Assess the Safety and Protective Efficacy of the Combination Malaria Vaccine Candidate Regimen of RTS,S/AS01B + ChAd63 and MVA Encoding ME-TRAP and Also RTS,S/AS01B Alone.
OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.
View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.
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