The invention presents vaccine formulations comprising highly antigenic epitopes identified within the semi-conserved loop-I of domain III that are capable of eliciting parasite growth inhibitory antibodies. The cyclized or linear peptides can be applied by known adjuvants or be encapsulated by or attached onto the surface of liposomes or virosomes (IRIVs) which serve as human compatible antigen delivery systems. Both cyclized and linear versions of the peptide antigens are surprisingly effective in eliciting immune responses that are cross-reactive with parasite-expressed AMA-1.