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Efficacy of Malaria Vaccines in Kenyan Adults

11. december 2013 opdateret af: University of Oxford

Efficacy Study of ChAd63MVA ME-TRAP Prime-boost Vaccination Against Plasmodium Falciparum Infection.

Malaria transmission is falling in some parts of Africa as bed nets and anti-malarials become more widely available. However, transmission still persists and it appears that additional control measures are required. The leading malaria vaccine candidate in development is RTS,S which has efficacy against clinical malaria measured at 30-50% in the field. This partial protection might be enhanced by combination with other components. The other vaccination approach that has produced repeatable efficacy in humans is the use of viral vectors to induce T cell responses. Previous attempts with this vaccine approach have been effective in challenge studies in Oxford, but ineffective in the field, probably because of reduced immunogenicity.

Recently, studies in Oxford, Kenya and the Gambia have shown higher levels of immunogenicity by using a chimpanzee adenovirus (ChAd63) followed by an attenuated vaccinia virus (modified vaccinia Ankara) to deliver the pre-erythrocytic antigen, multiple epitope string with thrombospondin- related adhesion protein (ME-TRAP).

The increase in immunogenicity has lead to sterile protection in 3 out of 14 volunteers and partial protection in 5 out of 14 volunteers in challenge studies.

The investigators propose a Phase 2b study of 120 healthy adult men in Kenya. The investigators will assess the efficacy and further evaluate the immunogenicity and safety profile of the vaccine regimen. The investigators also intend to assess the correlates of efficacy and natural immunity.

Studieoversigt

Status

Afsluttet

Betingelser

Intervention / Behandling

Undersøgelsestype

Interventionel

Tilmelding (Faktiske)

120

Fase

  • Fase 2

Kontakter og lokationer

Dette afsnit indeholder kontaktoplysninger for dem, der udfører undersøgelsen, og oplysninger om, hvor denne undersøgelse udføres.

Studiesteder

  • Kenya
      • Kilifi, Kenya, PO Box 230, 80108
        • KEMRI/Wellcome Trust Programme, Centre for Geographic Medicine Research - Coast

Deltagelseskriterier

Forskere leder efter personer, der passer til en bestemt beskrivelse, kaldet berettigelseskriterier. Nogle eksempler på disse kriterier er en persons generelle helbredstilstand eller tidligere behandlinger.

Berettigelseskriterier

Aldre berettiget til at studere

18 år til 50 år (Voksen)

Tager imod sunde frivillige

Ja

Køn, der er berettiget til at studere

Han

Beskrivelse

Inclusion Criteria:

  • Consenting adult males aged 18 - 50 years in good health.
  • Will remain resident in the study area for the study duration.
  • Able and willing (in the Investigator's opinion) to comply with all study requirements
  • Informed Consent

Exclusion Criteria:

  • Any significant medical disease, disorder or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data
  • Hypersensitivity to Verorab, the trial vaccines or the antimalarial used.
  • History of allergic disease or reactions likely to be exacerbated by any component of the vaccines, e.g. egg products, kathon, neomycin
  • History of splenectomy.
  • Haemoglobin less than 10.0 g/dl
  • Clinically significant abnormalities of laboratory screening tests (full blood count, ALT, creatinine levels).
  • Blood transfusion within the month preceding enrolment.
  • History of vaccination with previous experimental malaria vaccines or other vaccines likely to impact on findings of study (e.g. other MVA or adenovirus vectored vaccines)
  • Administration of any other vaccine or immunoglobulin within 2 weeks before vaccination.
  • HIV or Hepatitis B surface antigen seropositivity.
  • Current participation in another clinical trial or recent participation within 12 weeks of this study.
  • Any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial.
  • Likelihood of travel away from the study area

Studieplan

Dette afsnit indeholder detaljer om studieplanen, herunder hvordan undersøgelsen er designet, og hvad undersøgelsen måler.

Hvordan er undersøgelsen tilrettelagt?

Design detaljer

  • Primært formål: Forebyggelse
  • Tildeling: Randomiseret
  • Interventionel model: Parallel tildeling
  • Maskning: Enkelt

Våben og indgreb

Deltagergruppe / Arm
Intervention / Behandling
Eksperimentel: ChAd63 ME-TRAP and MVA ME-TRAP
ChAd63 ME-TRAP / MVA ME-TRAP heterologous prime-boost immunisation
Biologisk: ChAd63 ME-TRAP / MVA ME-TRAP prime-boost immunisation
ChAd63 ME-TRAP: 5 x 10^10vp MVA ME-TRAP: 2 x 10^8 pfu
Aktiv komparator: Rabies vaccine
2 x 2.5IU Verorab
Biologisk: Rabies vaccine
2 x 2,5 IE Verorab
Andre navne:
  • Verorab

Hvad måler undersøgelsen?

Primære resultatmål

Resultatmål
Foranstaltningsbeskrivelse
Tidsramme
Vaccine Efficacy
Tidsramme: 18 weeks
The first episode of P.falciparum infection positive by PCR, for P.falciparum.
18 weeks

Sekundære resultatmål

Resultatmål
Foranstaltningsbeskrivelse
Tidsramme
Vaccine immunogenicity
Tidsramme: 24 weeks

Measures of immunogenicity will include:

Ex vivo ELISPOT responses to overlapping pools of ME - TRAP peptides. Cultured ELISPOT responses to overlapping pools of ME - TRAP peptides. ICS by flow cytometry for cell mediated immune responses ELISA for antibodies to malaria antigens
24 weeks
Reactogenicity
Tidsramme: 24 weeks
All solicited and unsolicited local and systemic vaccine- linked adverse events (AEs) including clinically significant laboratory abnormalities.
24 weeks

Samarbejdspartnere og efterforskere

Det er her, du vil finde personer og organisationer, der er involveret i denne undersøgelse.

Sponsor

University of Oxford

Samarbejdspartnere

European and Developing Countries Clinical Trials Partnership (EDCTP)

Datoer for undersøgelser

Disse datoer sporer fremskridtene for indsendelser af undersøgelsesrekord og resumeresultater til ClinicalTrials.gov. Studieregistreringer og rapporterede resultater gennemgås af National Library of Medicine (NLM) for at sikre, at de opfylder specifikke kvalitetskontrolstandarder, før de offentliggøres på den offentlige hjemmeside.

Studer store datoer

Studiestart

1. marts 2012

Primær færdiggørelse (Faktiske)

1. august 2012

Studieafslutning (Faktiske)

1. august 2012

Datoer for studieregistrering

Først indsendt

14. august 2012

Først indsendt, der opfyldte QC-kriterier

14. august 2012

Først opslået (Skøn)

16. august 2012

Opdateringer af undersøgelsesjournaler

Sidste opdatering sendt (Skøn)

12. december 2013

Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier

11. december 2013

Sidst verificeret

1. december 2013

Mere information

Begreber relateret til denne undersøgelse

Yderligere relevante MeSH-vilkår

Andre undersøgelses-id-numre

  • VAC046

Disse oplysninger blev hentet direkte fra webstedet clinicaltrials.gov uden ændringer. Hvis du har nogen anmodninger om at ændre, fjerne eller opdatere dine undersøgelsesoplysninger, bedes du kontakte register@clinicaltrials.gov. Så snart en ændring er implementeret på clinicaltrials.gov, vil denne også blive opdateret automatisk på vores hjemmeside .

Kliniske forsøg med Malaria

Kliniske forsøg med Rabies vaccine

Søg i lignende forsøg

Sponsorer og samarbejdspartnere

Medicinske tilstande

Narkotikainterventioner

CROs by country

CROs in Pakistan

Betingelser

Sjældne sygdomme

Narkotikainterventioner

Kosttilskud

Sponsor / samarbejdspartnere

Placeringer

Abonner