Table 1:
(a) An overview of selected promising Plasmodium vivax vaccine candidates that have progressed into clinical trials with their correlates of protection and vaccine outcomes
| Candidate Vaccine/platform | Host (Clinical & preclinical studies) | Correlates of protection | Outcome | Progress |
|---|---|---|---|---|
| Blood-stage candidates | ||||
| PvDBPII | Phase 1a (UK adults) NCT01816113 | Antibodies against PvDBPII | No serious adverse events. Across all vaccinated individuals median polyclonal IgG EC50 values were comparable in PvDBPII-DARC in vitro binding. | Completed [1] |
| PvDBPII/GLA-SE | Phase 1 (34 Indian males) CTRI/2016/09/007289 |
PvDBPII-specific antibodies | No adverse events were observed. 50μg treatment, 82% mean binding-inhibitory activity was observed in PvDBPII-DARC binding assay at day 180 |
Completed by PATH/MVI [2] |
| Pre-erythrocytic candidates | ||||
| P. vivax irradiated sporozoites | Phase I/IIa (Colombia, adults) NCT01082341 |
Anti- PvCSP IgG1 levels correlates with protection | Partial protection observed in 42% of the Fy+ volunteers. | MVDDC, NHLBI/NIH [3] |
| PvCSP- derived long synthetic peptides, Allohydrogel Montanide ISA 720 51 | Phase 1b (Colombia adults) NCT01081847 | Antibody responses | Transient pain at injection site and induration occurred in the Montanide 50 μg group, PBMCs from all groups secreted IL-5 and IFNγ. | Completed by MVDDC [4] |
| VMP001-AS01B | Phase I/IIa (USA, adults) NCT01157897 |
Antibody titers | Significant delay in infection patency observed in 59% of vaccinated subjects. | Ongoing studies by WRAIR, MVI, GSK [5] |
| Sexual-stage candidates | ||||
| Pvs25- Recombinant Pvs25, Montanide ISA51 | Phase I (USA, adults) NCT00295581 |
Antibody responses correlated with transmission blocking activity | High reactogenicity observed | Completed by DIR/NIAID, JHSPH [6] |
PvCSP- Plasmodium vivax circumsporozoite protein
PvDBPII- P. vivax Duffy Binding protein region II
PvDBPII/GLA-SE- recombinant P. vivax DBP region II formulated with glucopyranosyl lipid adjuvant-stable emulsion
DARC- Duffy antigen receptor for chemokines
VMP001- Vivax malaria protein 001
PBMC- Peripheral blood mononuclear cells
cPvMSP1- Chimeric Plasmodium vivax Merozoite surface protein 1
Pvs25- Ookinete surface protein
LLPCs- Long-lived plasma cells