Near the end of the linked malaria article, it says:
Bucala and Geall have placed their vaccine in the hands of the Oxford University institution that facilitated the AstraZeneca COVID-19 vaccine. It is one of the only places in the world that is doing phase 1 studies in malaria, meaning researchers infect human volunteers with the disease after immunizing them.
So it sounds like maybe they are in act doing human challenge trials.
Near the end of the linked malaria article, it says:
So it sounds like maybe they are in act doing human challenge trials.