(Reuters) – The World Health Organization on Monday was cautious about approving the use of plasma recovered from COVID-19 patients to treat those who are sick, saying the evidence for its effectiveness remains “poor. quality “even if the United States has. issued an emergency authorization for such therapy.
So-called convalescent plasma, which has long been used to treat disease, has the latest political flash point in the race to locate treatments for COVID-19.
The US Food and Drug Administration (FDA) authorized its use Sunday after President Donald Trump blamed the company for the deployment of vaccines and therapies for political reasons.
The strategy is to take antibody-rich plasma from patients who have suffered from COVID-19 and give it to those with severe active infections in the hope that they will do so more quickly.
Soumya Swaminathan, a lead scientist at the WHO, said that only a few clinical trials with convalescent plasma have produced effects and the evidence, at least so far, has been compelling enough to support it, beyond its use as an experimental therapy. Although some trials have shown benefits, he said, they were small and his data, so far, was inconclusive.
“At the moment this is very low-quality evidence,” Swaminathan told a news conference. “Therefore, we proposed that convalescent plasma is an experimental therapy, it deserves further evaluation in well-designed randomized clinical trials. “
The evidence is conflicting: a Chinese test showed that plasma from other people who have recovered from the coronavirus did not notice a difference in hospitalized patients, while the joint investigation showed that it would possibly decrease the threat of death.
One challenge, Swaminathan added, is the variability of the plasma, as it comes from many other people, resulting in a less standardized product than laboratory-made monoclonal antibodies.
Bruce Aylward, senior adviser to the World Health Organization, added that beyond the effectiveness of plasma, there were also potential protection hazards that need to be considered.
“There are a number of effects,” Aylward said, ranging from mild fever to severe lung damage to circulatory overload. “For this reason, the effects of clinical trials are incredibly important. “
The US National Institutes of Health announced this month that they will award several million for a mid-term convalescent plasma test.
Reporting through John Miller in Zurich, Stephanie Nebehay in Geneva, Kate Kelland in London; Editing via Jon Boyle and Giles Elgood
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