American Association for the Advancement of Science, Science Translational Medicine, 704(15), 2023
DOI: 10.1126/scitranslmed.adf1782
Full text: Unavailable
There are no licensed vaccines againstPlasmodium vivax. We conducted two phase 1/2a clinical trials to assess two vaccines targetingP. vivaxDuffy-binding protein region II (PvDBPII). Recombinant viral vaccines using chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) vectors as well as a protein and adjuvant formulation (PvDBPII/Matrix-M) were tested in both a standard and a delayed dosing regimen. Volunteers underwent controlled human malaria infection (CHMI) after their last vaccination, alongside unvaccinated controls. Efficacy was assessed by comparisons of parasite multiplication rates in the blood. PvDBPII/Matrix-M, given in a delayed dosing regimen, elicited the highest antibody responses and reduced the mean parasite multiplication rate after CHMI by 51% (n= 6) compared with unvaccinated controls (n= 13), whereas no other vaccine or regimen affected parasite growth. Both viral-vectored and protein vaccines were well tolerated and elicited expected, short-lived adverse events. Together, these results support further clinical evaluation of the PvDBPII/Matrix-MP. vivaxvaccine.