A Study of the Safety and Effectiveness of Two New Malaria Vaccines
Condition: Malaria
MeSH terms: Malaria
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      This study aims to test the safety of two new malaria vaccines AdCh63 MSP1 and MVA MSP1.
      These vaccines consist of inactivated viruses which have been modified - so they cannot
      reproduce (replicate) in humans, and also to include genetic material (genes) for malaria
      proteins which are expressed by the malaria parasite during blood stage infection. The
      vaccines are designed to stimulate an immune response to these malaria proteins
      (immunogenicity describes the nature and magnitude of this immune response), to provide
      protection against malaria infection. This protection has been demonstrated in nonhuman
      studies. Although these vaccines have not been given to humans before, similar vaccines using
      the same viruses with different malaria genes have been given to humans before. In these
      studies, the vaccines have been shown to be safe. They have also provided evidence from
      laboratory tests of immunogenicity. In this study the investigators main aim is to ensure
      these new vaccines given alone and in combination are safe. The investigators will increase
      the dose of the first vaccine (AdCh63 MSP1) given to volunteers if the initial dose is safe.
      The investigators also wish to ensure that challenging a small number of volunteers who have
      received both vaccines with malaria infection from the bites of infected mosquitos(sporozoite
      challenge) is safe. Sporozoite challenge has been widely used in humans to test the
      effectiveness of malaria vaccines and is considered a well established, reliable, predictable
      and safe system.In the study the investigators will also look for evidence of immunogenicity
      of these new vaccines, and whether there is any delay to developing malaria following
      sporozoite challenge. The study will be conducted at the University of Oxfords Centre for
      Clinical Vaccinology and Tropical Medicine (CCVTM). The challenge part of the study will take
      place at the insectary at Imperial College, (Infection and Immunity Section)in London.
    


Intervention name(s): AdCh63-MSP1 (lower dose) vaccine and MVA-MSP1 vaccine; AdCh63-MSP1 vaccine (higher dose) and MVA-MSP1 vaccine followed by challenge
Intervention type(s): Biological; Biological
Intervention description(s): Group 1A: single dose of AdCh63-MSP1 vaccine 5 x 10^9 vp administered IM. Group 1B: single dose of AdCh63-MSP1 vaccine 5 x 10^9 vp administered IM followed by a single dose of MVA-MSP1 vaccine 5 x 10^8 vp administered IM 8 weeks later; Group 2A: single dose of AdCh63-MSP1 vaccine 5 x 10^10 vp administered IM. Group 2B: single dose of AdCh63-MSP1 vaccine 5 x 10^10 vp administered IM followed by a single dose of MVA-MSP1 vaccine 5 x 10^8 vp administered IM 8 weeks later. Group 2C: single dose of AdCh63-MSP1 vaccine 5 x 10^10 vp administered IM followed by a single dose of MVA-MSP1 vaccine 5 x 10^8 vp administered IM 8 weeks later and subsequent sporozoite malaria challenge 12-28 days post second vaccination
Intervention MeSH terms: Vaccines
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Vaccine; Safety; Immunogenicity; Protection; Sporozoite challenge