March 29, 2015

Research Roundup: clinical trials for experimental Ebola vaccines, genetic traits that affect malaria risk, and progress toward a hookworm vaccine

Senior Program Assistant

The National Institute of Allergy and Infectious Diseases (NIAID) announced last week that two experimental Ebola vaccines appear to be safe for widespread use, based on early results of clinical trials in Liberia. NIAID will now expand its trials to include as many as 1,500 volunteers, testing the vaccine candidates for efficacy. Volunteers will receive either the vaccine candidate developed by GlaxoSmithKline, another developed by NewLink Genetics Corp, or a placebo. Researchers will examine the immune response to the vaccines to see if participants develop antibodies against Ebola. None of the participants will be intentionally exposed to the Ebola virus.

Scientists at NIAID have identified several genetic conditions that affect one’s risk for malaria, and which primarily manifest as red blood cell abnormalities. The researchers followed 1,543 children in Mali for three years, during which time they recorded 4,091 cases of malaria. Genetic disorders that either decreased the production of hemoglobin—the protein that transports oxygen in the blood—or led to the creation of hemoglobin C, an abnormal form of the protein, were associated with increased risk for malaria. Two genetic traits—HbAS and homozygous X-linked G6PD deficiency—appear to protect against malaria. The HbAS gene was not only associated with lower risk for malaria, but with less severe cases of malaria in children who contracted it.

Researchers at Cornell University have mapped the genome of Ancylostoma ceylanicum, one of two species of hookworm that infect humans. The study identified 31,000 different genes, including those that are active in hookworms during infection. Scientists believe that as many as 70 of those genes could be promising targets for new drugs or vaccines, and plan to start testing experimental vaccines in hamsters this year.