Table 1.

An example of 4313, 4325 and 4337 (AMA-1 derived) HABP-induced humoral immune response and protective immunity and that of their modified analogues [87, 83, 88] Some of the amino acid replacements leading to the breaking of the immunological code of silence. Antibody titres were determined by immunofluorescence antibody assay (IFA) 15 days after the second and 15 days after the third immunization. Protection was defined as the complete absence of parasites in immunized monkey blood for 15 days following challenge. All control monkeys reached ≥6% parasitaemia by days 6–8; they were then treated, cured and released back into the Amazon jungle. ND, not determined. Modified HABP groups, A: immunogenic protection-inducer; B: long-lasting high antibody titre non-protection inducers; D: short-lived non-protection inducers; E: Non-immunogenic non-protection inducer. Boxed are the modified HABPs for which the ¹H NMR structure has been shown.