Controlled human malaria infection with a clone of Plasmodium vivax with high quality genome assembly.
Minassian AM., Themistocleous Y., Silk SE., Barrett JR., Kemp A., Quinkert D., Nielsen CM., Edwards NJ., Rawlinson TA., Ramos Lopez F., Roobsoong W., Ellis KJ., Cho J-S., Aunin E., Otto TD., Reid AJ., Bach FA., Labbé GM., Poulton ID., Marini A., Zaric M., Mulatier M., Lopez Ramon R., Baker M., Mitton CH., Sousa JC., Rachaphaew N., Kumpitak C., Maneechai N., Suansomjit C., Piteekan T., Hou MM., Khozoee B., McHugh K., Roberts DJ., Lawrie AM., Blagborough AM., Nugent FL., Taylor IJ., Johnson KJ., Spence PJ., Sattabongkot J., Biswas S., Rayner JC., Draper SJ.
Controlled human malaria infection (CHMI) provides a highly informative means to investigate host-pathogen interactions and enable in vivo proof-of-concept efficacy testing of new drugs and vaccines. However, unlike Plasmodium falciparum, well-characterized P. vivax parasites that are safe and suitable for use in modern CHMI models are limited. Here, two healthy malaria-naïve UK adults with universal donor blood group were safely infected with a clone of P. vivax from Thailand by mosquito-bite CHMI. Parasitemia developed in both volunteers and, prior to treatment, each volunteer donated blood to produce a cryopreserved stabilate of infected red blood cells. Following stringent safety screening, the parasite stabilate from one of these donors ("PvW1") was thawed and used to inoculate six healthy malaria-naïve UK adults by blood-stage CHMI, at three different dilutions. Parasitemia developed in all volunteers, who were then successfully drug treated. PvW1 parasite DNA was isolated and sequenced to produce a high quality genome assembly by using a hybrid assembly method. We analysed leading vaccine candidate antigens and multigene families, including the Vivax interspersed repeat (VIR) genes of which we identified 1145 in the PvW1 genome. Our genomic analysis will guide future assessment of candidate vaccines and drugs, as well as experimental medicine studies.