“…In this study, four multi-dose priming regimens, with or without delayed boosting, were evaluated, all of which using doses of 9 x 10 5 PfSPZ delivered iv: days 1, 3, 5, 7 and 113; days 1, 3, 5 and 7; days 1, 3, 5, 7 and 29; and days 1, 8, and 29. A significant 51.3% protection was only observed for the regimen in which the vaccine was administered on a 4-week schedule, on days 1, 8, and 29 ( 63 ). The delayed boosting immunization schedule yielded a protective efficacy of ~40%, which is similar to that observed in the USA trial ( 62 ), but was not statistically significant ( 63 ).…”