Table 2.

Protection against blood-stage versus sporozoite challenge by CPS immunization

Prepatent period, d, median (range)
ChallengeProtected/total no. of volunteersProtection, %Thick smearPCRBlood-stage parasite multiplication rate, median (range)
ImmunizedSporozoite5/5100N/AN/A*N/A
Blood stage0/908.0 (7.0–8.3)5.0 (3.0–5.3)8 (6-18)
ControlSporozoite0/5012.3 (9.3–12.3)9.0 (7.0–10.0)10 (5-23)
Blood stage0/508.0 (8.0–8.3)5.0 (2.0–6.3)14 (7-24)
  • * One subject became PCR positive on day 21 after challenge. N/A, not applicable.