Anopheles albimanus mosquitoes Buenaventura strain, have been reared under laboratory conditions at IDIV in Cali for about 10 years. This mosquito colony has been successfully used to regularly produce sporozoites14,16 and for studies on malaria transmission-blocking immunity.17 Here, mosquitoes were fed within 2-3 hours after the P. vivax-infected blood (gametocytemia ≥ 0.1%) was collected in Buenaventura. The 15 mL blood was centrifuged at 500 × g for 5 minutes at room temperature, plasma was removed, and cells were washed once with RPMI 1640 medium (Gibco Cell Culture Systems, Invitrogen, Grand Island, NY ). Parasitized erythrocytes were reconstituted to 50% hematocrit with pooled human AB non-immune, complement-inactivated serum obtained from the Red Cross blood bank and were used to infect lots of 4,000 female mosquitoes (3-4 days old) using a water-jacketed membrane apparatus at 37°C, described previously.14 Infected mosquitoes were maintained under strict biosafety conditions at 27 ± 1°C and relative humidity of 82% and a sugar solution supplemented with 0.05% para-aminobenzoic-acid was provided.18 Samples of fed mosquitoes were dissected and microscopically examined 7-8 days after the blood meal to determine the presence of oocysts in the midgut, and on Days 14 and 15 to assess the presence of sporozoites in salivary glands.19 Mosquito infections were graded as 1+ (1-10 spz), 2+ (11-100 spz), 3+ (101-1000 spz), and 4+ (> 1001 spz).7