Genetic Diversity

"Scientists and health officials worldwide have made eradication of" malaria "a priority, with an effective and broadly protective vaccine a critical step toward that goal. Malaria -- a parasite spread to humans through mosquito bites -- is prevented by avoiding mosquito bites using bed nets or by killing mosquitoes with insecticides. The parasite is treatable using medications, although drug resistance is a relatively common problem. According to the World Health Organization, a child dies of malaria every 30 seconds" (University). Currently, "no approved vaccine for malaria" exists, but "various experimental vaccines are in development" (University). As of now, "vaccines directed against the blood stages of Plasmodium falciparum malaria [a deadly strain] are intended to prevent the parasite from invading and replicating within host cells. No blood-stage malaria vaccine has shown clinical efficacy in humans" (Takala).

"Researchers at the University of Maryland School of Medicine Center for Vaccine Development (CVD) have charted the extreme genetic differences that occur over time in the most dangerous malaria parasite in the world" (University). They "examined the extent and within-host dynamics of genetic diversity in the blood-stage malaria vaccine" and concluded that this "extreme diversity may pose a serious obstacle" to the creation of an effective vaccine.

"The CVD study suggests that developing a broadly protective vaccine for malaria may be challenging because the parasite's genetic makeup is so variable, constantly changing" (University).

Sources:
Takala, Shannon L. et al. "Extreme Polymorphism in a Vaccine Antigen and Risk of Clinical Malaria: Implications for Vaccine Development." Sci Transl Med 14 October 2009:
Vol. 1, Issue 2, p. 2ra5.

University of Maryland Medical Center. "Extreme Genetic Variability In Malaria Parasite Found." ScienceDaily 15 October 2009. 21 October 2009 .