Chimpanzees possess unique genetic mechanisms that help them combat malaria more effectively than humans. Malaria, a disease that continues to claim millions of lives worldwide, remains one of the most persistent and challenging public health crises. Despite decades of progress in treatment and prevention, the disease still poses a significant threat to global health.
With nearly half of the world’s population at risk, particularly in sub-Saharan Africa, efforts to eradicate malaria have been complicated by the evolving nature of the disease, the parasites that cause it, and the mosquitoes that transmit it. Despite global investment exceeding billions annually in malaria control and elimination, progress has stalled in recent years. The Covid-19 pandemic further disrupted malaria prevention and treatment services, reversing years of progress in many endemic regions.
While much of the focus on malaria has been on human-centered solutions, new research has turned to an unlikely source for understanding and potentially combating the disease: chimpanzees. Findings suggest that chimpanzees have evolved unique genetic mechanisms that help them resist malaria, offering potential new avenues for human treatment and prevention strategies.
Malaria is caused by Plasmodium parasites, transmitted through the bite of infected Anopheles mosquitoes. Research has revealed that chimpanzees possess genetic mechanisms that help them combat malaria more effectively than humans. A collaborative study involving researchers across multiple continents provides compelling evidence that chimpanzees have evolved specialized genetic defenses against the disease.
Chimpanzees share approximately 98 per cent of their DNA with humans, making them crucial for understanding our evolutionary history and the biological foundations of diseases such as malaria. This close genetic relationship means findings from chimpanzee research could significantly advance human malaria prevention and treatment strategies.
The research reveals a fascinating pattern: chimpanzees living in forested habitats, where malaria parasites are abundant, have evolved specific genetic adaptations absent in their savannah-dwelling counterparts. These forest environments, with their higher humidity and denser mosquito populations, have exerted stronger selective pressure for malaria resistance.
To conduct this comprehensive study, researchers collected fecal samples from hundreds of wild chimpanzees across various populations representing all four chimpanzee subspecies. By analyzing the exomes the protein-coding regions of the genome scientists identified genetic variations specifically linked to malaria resistance.
Key genes such as GYPA, which is involved in the invasion of red blood cells by the malaria parasite, and HBB, which plays a role in sickle cell anemia and provides partial malaria resistance in humans, have undergone selection in forest-dwelling chimpanzee populations. While both humans and chimpanzees face the threat of malaria, they have developed different genetic strategies to combat it.
Humans have evolved specific mutations like the sickle cell trait and G6PD deficiency that provide partial protection against malaria in certain populations. These adaptations come at a cost carriers of these traits can suffer from genetic disorders. Unlike humans, who rely on such mutations to reduce malaria severity, chimpanzees have evolved more intrinsic resistance mechanisms that prevent the malaria parasite from thriving in their bodies.
Among these adaptations is the DARC receptor gene, which regulates the entry of Plasmodium parasites into red blood cells, and specialized HLA variants that enhance immune surveillance against the parasite. These genetic factors allow chimpanzees to mount a more comprehensive defense against malaria infection.
One of the study’s most significant findings is that both humans and chimpanzees appear to have limited genetic pathways for evolving malaria resistance. This suggests that there are only a few biological routes to effectively combat the disease. The fact that malaria resistance follows a few evolutionary pathways has enormous implications for vaccine development. It means researchers do not need to explore an endless range of genetic variations. Instead, they can focus on mimicking these key genetic modifications that have proven effective in chimpanzees.
The research on chimpanzee malaria resistance is already informing vaccine development strategies. Chimpanzee research has contributed to the development of drugs like Tafenoquine, which treats Plasmodium vivax malaria, and vaccines such as RTS,S/AS01, the first malaria vaccine recommended for widespread use in children in moderate to high transmission regions. More recently, the R21/Matrix-M vaccine, which has shown up to 77 per cent efficacy in clinical trials, represents another promising advance. The Kenya Medical Research Institute has been actively involved in testing this vaccine, building on its earlier pivotal role in developing RTS,S/AS01.
