LONDON (AP) — Giving the blood of Ebola survivors to patients didn't seem to make a difference, doctors found in the biggest study so far on the approach, prompting some scientists to say it's time to abandon the strategy.
With no licensed treatment for the devastating disease, doctors have sometimes used blood from survivors to treat the sick, hoping its infection-fighting antibodies might help patients defeat the virus. It seemed to help some patients in the past but there was no clear proof. Amid the world's biggest outbreak of Ebola in West Africa in 2014, scientists decided to put the treatment to the test in Guinea.
At a clinic in the capital Conakry, scientists found no difference in survival between 84 patients who got survivor blood compared to about 400 patients treated some five months earlier, according to the study published in New England Journal of Medicine Thursday.
"We would have liked to have seen more dramatic results," said Johan van Griensven of the study in Guinea, the paper's lead author. "But this doesn't mean (blood) plasma treatment doesn't work by definition."
He said antibody levels are often low in patients who have only recently recovered from Ebola and that doctors might need to use blood from long-term survivors to get a better effect.
Van Griensven and colleagues studied people who got two transfusions of plasma — the clear part of blood that contains antibodies — in Guinea last year. The plasma came from 58 Ebola survivors, most of whom had recovered from Ebola within six months of donating blood and are thought to have immunity to the strain. Scientists didn't know what the antibody levels were in the donated plasma and said it was possible some plasma was more potent than others.
A similar study on the blood of Ebola survivors in Liberia was discontinued because there weren't enough patients and another study in Sierra Leone had treated just three patients by last October. To date, the outbreak first noted in 2014 has killed more than 11,000 people in West Africa. Ebola was declared over in Guinea last month, the first time all three affected countries have stopped the virus' spread.
Some said the disappointing results should be enough to convince scientists to abandon this strategy.
"From the data presented, it doesn't look like this is worth pursuing," said Thomas Geisbert, an Ebola expert at the University of Texas Medical Branch at Galveston, who has done similar studies in monkeys. He was not connected to the latest research.
"The idea that antibodies from a person who survived Ebola could save lives was always a long shot, but it was too good an idea not to test," said Ben Neuman, a virologist at Britain's University of Reading.
"The most valuable thing this study provides is clarity," Neuman wrote in an email. "Finally, the idea of using (survivor's blood) can be crossed off the list and other more promising drugs and vaccines can be tested."