Phase 1 safety and immunogenicity trial of the Plasmodium falciparum blood-stage malaria vaccine AMA1-C1/ISA 720 in Australian adults.

Vaccine. 2010 Jan 2;

Authors: Pierce MA, Ellis RD, Martin LB, Malkin E, Tierney E, Miura K, Fay MP, Marjason J, Elliott SL, Mullen GE, Rausch K, Zhu D, Long CA, Miller LH

A Phase 1 trial was conducted in malaria-naïve adults to evaluate the recombinant protein vaccine apical membrane antigen 1-Combination 1 (AMA1-C1) formulated in Montanide((R)) ISA 720 (SEPPIC, France), a water-in-oil adjuvant. Vaccinations were halted early due to a formulation issue unrelated to stability or potency. Twenty-four subjects (12 in each group) were enrolled and received 5 or 20mug protein at 0 and 3 months and four subjects were enrolled and received one vaccination of 80mug protein. After first vaccination, nearly all subjects experienced mild to moderate local reactions and six experienced delayed local reactions occurring at Day 9 or later. After the second vaccination, three subjects experienced transient grade 3 (severe) local reactions; the remainder experienced grade 1 or 2 local reactions. All related systemic reactogenicity was grade 1 or 2, except one instance of grade 3 malaise. Anti-AMA1-C1 antibody responses were dose dependent and seen following each vaccination, with mean antibody levels 2-3 fold higher in the 20mug group compared to the 5mug group at most time points. In vitro growth-inhibitory activity was a function of the anti-AMA1 antibody titer. AMA1-C1 formulated in ISA 720 is immunogenic in malaria-naïve Australian adults. It is reasonably tolerated, though some transient, severe, and late local reactions are seen.

PMID: 20051276 [PubMed - as supplied by publisher]