Safety and Immunogenicity of a Recombinant Nonglycosylated Erythrocyte Binding Antigen 175 Region II Malaria Vaccine in Healthy Adults Living in an Area Where Malaria is Not Endemic

Publication Type
Journal Article
Year of Publication
El Sahly, H; Patel, S; Atmar, R; Lanford, T; Dube, T; Thompson, D; Sim, BK; Long, C; Keitel, W
Clinical and Vaccine Immunology
Start Page
Date Published
Adjuvants-Immunologic; Adolescent; Adult; Aluminum Compounds; Antibodies- Protozoan; Antigens-Protozoan; Enzyme-Linked Immunosorbent Assay; Female; Human Experimentation; Immunization-Secondary; malaria; Malaria-Falciparum; Male; Phosphates; Vaccines
Erythrocyte binding antigen region II (EBA-175) is a conserved antigen of Plasmodium falciparum that is involved in binding of the parasite to the host's erythrocytes. We evaluated the safety and immunogenicity of a recombinant EBA-175 vaccine with aluminum phosphate adjuvant in healthy young adults living in the United States. Eighteen subjects/group received ascending doses (5, 20, 80, or 160 μg) of the vaccine at 0, 1, and 6 months; 8 subjects received placebo. Most of the injection site and systemic reactions were mild to moderate in intensity. After 2 or 3 doses of the vaccine at any concentration, antibody levels measured by enzyme-linked immunosorbent assay were significantly higher than those for the placebo group. Sera from subjects who received 3 doses of the vaccine at any concentration inhibited the growth of erythrocyte-stage P. falciparum at low levels compared to sera from placebo recipients or preimmune sera. In conclusion, the EBA-175 vaccine with adjuvant was safe and immunogenic in malaria-naïve subjects.