Study of candidate malaria vaccine shows results in Ethiopia

Scientists recently studied the nature of humoral immune responses to a malaria vaccine candidate in two Ethiopian ethnic groups living in malaria-endemic regions.

In Ethiopia, the general population remains susceptible to unpredictable patterns of Plasmodium falciparum malaria epidemics, yet there is little information on the anti-malaria immune profile of the population living in endemic regions, according to

In the cross-sectional study, participants were diagnosed for infection microscopically and through the use of the rapid diagnostic test. Sera were tested for total immunoglobulin G against P. falciparum blood stage vaccine candidate GMZ2, as well as lgG subclasses against its subunits.

The study found that the Boditi group, found in the country's southern regions, had positive smears in eight percent of the cases, while the Shewa Robit group, found in the country's southern regions, had no smears test positive for P. falciparum.

The researchers concluded that a significantly higher antibody prevalence and level detected against GMZ2 compared to its subunits separately in naturally exposed populations suggests a synergistic effect of lgG subclasses and that GMZ2 could therefore be a more relevant blood-stage malaria vaccine than the candidate's individual components.

"Detection of high-level antibody responses in non-febrile, smear-negative individuals may possibly be an indication of a low-grade, asymptomatic sub-microscopic infection in the induction and maintenance of high-level malaria immunity," the researchers said, reports.