Table 2.
Immunization with Pysap1(−) sporozoites confers sterile protection against wild-type sporozoite challenge.
| Group | Primary dose (days of booster dose) | Challenge dose/days after last boost | No. protected/No. challengeda | Mean pre-patent period (days) |
|---|---|---|---|---|
| I | 10 000 (14, 28) | 10 000/7 | 9/9 | − |
| II | 10 000 (14, 28) | 10 000/(30)/(210) | 15/15/15 | −/− |
| III | 10 000 (14, 28) | 10 000/(30)/(210) | 10/10/10 | −/− |
| IV | 10 000 (14, 28) | MBb/(45)/(210) | 5/5/5 | −/− |
a
Each immunization group had an age-matched naïve control group (minimum three mice) that all became patent at day 3 after each PyWT sporozoite challenge.
b
Infection through mosquito bite (MB) by allowing a minimum of 10 PyWT female infected mosquitoes, with midgut oocyst infectivity higher than 90%, to bite one mouse for at least 10 min.