Immunization With Plasmodium Falciparum Sporozoites Under Chloroquine Versus Mefloquine Prophylaxis

Standard prophylactic regime: a loading dose of 300 mg on day 14 and day 17 and then 300 mg once a week, starting on day 21, for a total duration of 13 weeks. On day 0, day 3, day 7 and day 10, this group will receive a placebo.

Mefloquine prophylaxis, starting with a loading regime of split doses during the first three weeks: 125 mg on day 0, day 3, day 7, day 10, day 14 and day 17 and 250 mg once a week from day 21 onwards for a total duration of 13 weeks.

Group 1 and 2 will receive three immunizations with Plasmodium falciparum infected mosquito-bites. Group 3 will receive an equal number of uninfected mosquito-bites.

Exposure to the bites of 5 Plasmodium falciparum infected mosquitoes.

When thick smear positive, of ar day 21 after challenge, all volunteers will be treated with malarone.