Table 1.
Blood-stage vaccine candidates that showed significant effects in humans.a
| Trial | Vaccine formulation | Main outcome | Ref |
|---|---|---|---|
| Combination B (MSP1, MSP2, and RESA) | |||
| Phase IIb | E. coli expressed recombinant MSP1 (K1 strain), MSP2 (3D7), and RESA (FCQ-27/PNG) proteins with Montanide ISA720 adjuvant | No clinical protection, but strain-specific reduction in malaria infection: 78 out of 359 (22%) PCR samples showed 3D7 dimorphic form of MSP2 in the control groups, while 30/360 (8%) in the vaccine groups | [96] |
| AMA1 | |||
| Phase IIb | E. coli expressed recombinant AMA1 (3D7) protein with GSK AS02A adjuvant | No clinical protection, but strain-specific reduction in malaria cases. In 22 episodes (out of 271 total episodes observed during the trial) infected with AMA1-3D7 type parasites, 16 cases occurred in the control group, and another 6 cases in the vaccine group. | [97] |
| Phase IIa | E. coli expressed recombinant AMA1 (3D7) protein with GSK AS02A adjuvant | No significant difference in prepatent period or parasite growth rate after sporozoite challenge. However, significantly lower cumulative parasitemia during Day 7–9 after challenge in the vaccine group (n = 10) as compared to the unvaccinated infectivity control (n = 6). | [68]b |
| MSP3 | |||
| Phase Ib | MSP3 long synthetic peptide with aluminum hydroxide adjuvant | Significant reduction in risk of clinical malaria: 1.2 (15 μg dose) and 1.9 (30 μg dose) cases per 100 days per person in the vaccine groups (n = 15 each) while 5.3 in the control group (n = 15) | [98] |
| SE36 (SERA-5) | |||
| Phase Ib | E. coli expressed recombinant SERA-5 (Honduras-1) protein with aluminum hydroxide adjuvant | Significant reduction in risk of clinical malaria: Hazard ratio = 0.26 after adjustment of age and gender: the vaccine group (n = 66) was compared to the control group (n = 16) and newly enrolled unvaccinated individuals (n = 50) | [99] |
| MSP1 | |||
| Phase IIa | Recombinant chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) vectors encoding MSP1 | Significant difference in prepatent period after sporozoite challenge (n = 3 in the vaccine group and n = 6 in control) in the initial study, but not in the second study (n = 9 in vaccine and n = 6 in control) | [85] |
aClinical trials which were conducted with a multistage vaccine(s) are not included.
bThere were other vaccine groups in the trial, but only one group which showed a significant effect is shown.