5 0 % ▁in ▁inf ants ▁and ▁young ▁children . ▁On ▁ 2 3 ▁October ▁ 2 0 1 5 , ▁the ▁World ▁Health ▁Organ ization ' s ▁Str ateg ic ▁Ad vis ory ▁Group ▁of ▁Exper ts ▁on ▁Im mun ization ▁( SA GE ) ▁and ▁the ▁Mal aria ▁Policy ▁Ad vis ory ▁Committee ▁( MP AC ) ▁joint ly ▁recommended ▁a ▁pilot ▁implementation ▁of ▁the ▁v acc ine ▁in ▁Africa . ▁ ▁This ▁pilot ▁project ▁for ▁v acc ination ▁has ▁been ▁launched ▁on ▁ 2 3 ▁April ▁ 2 0 1 9 ▁in ▁Mal aw i , ▁on ▁ 3 0 ▁April ▁ 2 0 1 9 ▁in ▁Gh ana , ▁and ▁on ▁ 1 3 ▁September ▁ 2 0 1 9 ▁in ▁Ken ya . ▁ ▁History ▁ ▁Pot ential ▁mal aria ▁v acc ines ▁have ▁been ▁an ▁inten se ▁area ▁of ▁research ▁since ▁the ▁ 1 9 6 0 s . ▁SP f 6 6 ▁was ▁tested ▁extens ively ▁in ▁en demic ▁areas ▁in ▁the ▁ 1 9 9 0 s , ▁but ▁clin ical ▁tri als ▁showed ▁it ▁to ▁be ▁ins u fficient ly ▁effective . ▁Other ▁v acc ine ▁candidates , ▁target ing ▁the ▁blood - stage ▁of ▁the ▁mal aria ▁par as ite ' s ▁life ▁cycle , ▁have ▁also ▁been ▁ins u fficient ▁on ▁their ▁own . ▁Among ▁several ▁potential ▁v acc ines ▁under ▁development ▁that ▁target ▁the ▁pre - ery th ro cy t ic ▁stage ▁of ▁the ▁disease , ▁R TS , S