Scientists reported Wednesday that the experimental Ebola vaccine developed by GlaxoSmithKline did not result in any serious side effects, even producing desired immune responses in all 20 volunteers that are part of the early-stage clinical trial.
Carried out in Bethesda, Maryland, the clinical trial started back in September, scheduled to monitor volunteers for a 48-week period, and was primarily designed to test how safe the experimental vaccine was. Given the immune responses that manifested, GlaxoSmithKline is also hopeful that it would be effective.
"The safety profile is encouraging, as is the finding that the higher dose of vaccine induced an immune response quite comparable to that which has completely protected (lab) animals from Ebola," said Dr. Anthony Fauci, NIAID director.
Developed at the National Institute of Allergy and Infectious Disease and Okairos, a GlaxoSmithKline-acquired biotechnology company, the experimental vaccine features genetic material from two strains of Ebola, Zaire and Sudan, but doesn't actually contain a virus so its administration will not make anyone sick. Zaire is the strain of Ebola responsible for the outbreak currently ravaging West Africa.
The clinical trial is made up volunteers between the ages of 18 and 50, all healthy. Half of the volunteers were given lower doses of the experimental vaccine while the other half with higher doses. Within four weeks, all volunteers developed antibodies against Ebola in their bodies, with those given higher doses producing more.
Additionally, just how much of the experimental vaccine was administered also affected T cell production in the body, with seven out of the 10 people given higher doses producing a crucial type of T cell. However, out of the 10 given lower doses, only two produced the specific T cell. This outcome shows that higher doses are more beneficial but the problem is that this would make it more expensive and more challenging for a vaccine to be produced in large quantities.
The preliminary results of the clinical trial were published in the New England Journal of Medicine. Tulane University's Dr. Daniel Bausch wrote a commentary for the published work, calling the results of the clinical trial promising but cautioning that there exist a lot more challenges before the experimental vaccine will be deemed safe and effective.
GlaxoSmithKline has other clinical trials ongoing for another experimental Ebola vaccine also based off the Zaire strain. These clinical trials are being carried out in Switzerland, Mali and England. Another clinical trial is taking place in Maryland for a vaccine created by NewLink Genetics from Iowa.
