Experimental models of liver-stage malaria: Progress, gaps, and challenges

For decades, achieving malaria eradication has proven difficult. Plasmodium parasites first multiply asymptomatically in the liver before causing cyclic erythrocytic infections and clinical symptoms. Unlike other species, Plasmodium vivax can remain dormant for months or years as hypnozoites within hepatocytes. When these latent parasites reactivate, they cause clinical episodes in most vivax malaria cases. Thus, targeting the liver stage is essential to prevent disease progression and relapse. Current therapies are effective but pose risks for individuals with glucose-6-phosphate dehydrogenase deficiency. Consequently, developing and evaluating new antimalarial agents requires in vitro models that accurately represent intrahepatic parasite growth. Existing in vitro models have improved over time, but still face limitations. Recent advancements in cell culture have introduced organoids, which are three-dimensional, self-organizing cellular structures that recreate the microarchitecture and functions of native tissues. This review highlights the strengths and weaknesses of current experimental platforms and identifies critical gaps. We discuss how organoid technology can address these shortcomings, guiding improvements in liver-stage malaria models. Such advances will facilitate the development of preventive strategies and radical cures.