A phase I safety and immunogenicity trial with the candidate malaria vaccine RTS,S/SBAS2 in semi-immune adults in The Gambia

Am J Trop Med Hyg. 1999 Dec;61(6):865-8. doi: 10.4269/ajtmh.1999.61.865.

Abstract

RTS,S is a novel pre-erythrocytic malaria vaccine based on the circumsporozoite surface protein (CSP) of Plasmodium falciparum linked to hepatitis B surface antigen (HBs) and combined with a novel adjuvant system (SBAS2). We have conducted a Phase I trial with three doses of this vaccine given at 0, 1, and 6 months to 20 semi-immune, adult, male volunteers in The Gambia to assess its safety and immunogenicity. Eighteen of the 20 volunteers completed the study. There were no clinically significant local or systemic adverse events following each vaccination. Hematologic and biochemical indices before and two weeks after each vaccination showed no evidence of toxicity. Antibody titers to both CSP and HBs showed a significant increase after vaccination; these were the largest after the third dose. We conclude that the RTS,S/SBAS2 vaccine induces no significant toxicity in this semi-immune population and produces significant increases in antibody titers to CSP.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase I
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Antibodies, Protozoan / blood
  • Antigens, Protozoan / immunology
  • Dose-Response Relationship, Drug
  • Enzyme-Linked Immunosorbent Assay
  • Gambia
  • Hepatitis B Antibodies / blood
  • Hepatitis B Surface Antigens / blood
  • Hepatitis B Surface Antigens / immunology
  • Humans
  • Malaria Vaccines / administration & dosage
  • Malaria Vaccines / adverse effects*
  • Malaria Vaccines / immunology*
  • Malaria, Falciparum / blood
  • Malaria, Falciparum / prevention & control*
  • Male
  • Middle Aged
  • Plasmodium falciparum / immunology*
  • Plasmodium falciparum / isolation & purification
  • Protozoan Proteins / immunology
  • Reference Values
  • Vaccines, Synthetic / adverse effects
  • Vaccines, Synthetic / immunology

Substances

  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Hepatitis B Antibodies
  • Hepatitis B Surface Antigens
  • Malaria Vaccines
  • Protozoan Proteins
  • Vaccines, Synthetic
  • circumsporozoite protein, Protozoan