According to a field test of experimental treatment, treating Ebola victims using blood plasma donated by Ebola survivors has failed to notably raise the odds of recovering from the deadly virus.

The finding is based on the cases of 84 people, who had undergone treatment with plasma in Conakry, Guinea, with a hope that the antibodies in the fluid would aid patients fight off the virus the way they performed in the surviving donors.

The results published in the New England Journal of Medicine suggested that the death rate was 31% when plasma was used in comparison to 38% in a control group of 418 sufferers, who had undergone treatment in the same medical center and did not receive survivor plasma.

When the researchers considered other factors affecting survival, like victim’s age, the effect of plasma therapy was even less impressive.

While speaking to Reuters Health, chief author Dr. Johan van Griensven of the Institute of Tropical Medicine in Antwerp, Belgium said that certainly one dreams to a very strong cut in mortality, but they didn’t see this.

The study had a key drawback that it had no idea of how many virus-fighting antibodies were there in the donors’ plasma. The researchers wrote that this happened because Ebola virus disease, or EVD, is very dangerous, and analysis has to be done in laboratories using special safety equipment, which was not available in affected countries.

Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center in Nashville, said, “We might have anticipated there would be an effect with plasma from survivors”. Dr. William was not linked to the research.

He cautioned that the fact no benefit was visible didn’t mean that antibodies to Ebola will not be a good treatment. He added that the plasma donors might not have been recovered completely, due to which the antibodies might not have been enriched in fluid.