LONG TERM EFFICACY, SAFETY, REACTOGENICITY, AND IMMUNOGENICITY OF PHASE IIA, OPEN-LABEL, CONTROLLED STUDY FOR THE RTS, S/AS01B MALARIA VACCINE CANDIDATE ADMINISTERED AS STANDARD DOSES AT 0 AND 1 MONTHS AND 1/5TH STANDARD DOSE AT 7 MONTHS (DELAYED FRACTIONAL DOSE GROUP) AND ADMINISTERED AS THREE STANDARD DOSES ONE MONTH APART (0, 1, 2-MONTH GROUP) IN HEALTHY MALARIA-NAIVE VOLUNTEERS AGED 18-50 YEARS