Coronavirus: plasma transfusions not effective against the disease, WHO says

Published by Laurent P. · Published on 9 December 2021 at 14h28
Is plasma transfusion an effective solution against Covid? The WHO eventually addressed this matter and advises against this past December 6 after assessing data available. These data seem to show these tranfusions are useless and do not prevent severe illness and death.

Is plasma transfusion THE solution to fight against Covid? This question seems to split scientists who conducted several studies ont he matter, and each of them ended up with different and... mixed results. Among the latest known, the one released this past October in BMJ that comes to the conclusion that "convalescent plasma is ineffective for Covid-19". The cure is less powerful but more "versatile", unlike monoclonal antibodies treatments also being studied.

The final decision has been made this December 6, 2021. The World Health Organization addressed in a release and advises againsy the use of blood plasma from former sick. Why? "Current evidence shows that convalescent plasma does not improve survival or reduce the need for mechanical ventilation, while it has significant costs", WHO experts explained in the British Medical Journal.

This recommendation is based on the results of a total of 16 studies carried out on over 16,000 volunteers, all suffering from light to severe Covid. These results show the inefficiency of plasma but "also noted several practical challenges, such as the need to identify and test potential donors, as well as collect, store and administer donor plasma, which they say further limits its feasibility and applicability". The complexe character is actually a bad solution as now vaccines and therapies are available.

And yet, plasma transfusion was particularly promising, accoding to a study carried out in China and published in the highly respected scientific journal  PNAS, Proceedings of the National Academy of Sciences. How come? Thanks to plasma transfusions (and then of antibodies) from already cured people. According to this study, the first trials (still running) performed by searchers on a dozen volunteering patients from 34 to 78 years old had particularly encouraging results.

In this study, scientists noticed that symptoms in test patients (cough, breathing difficulties, fever and even chest pains) almost disappeared in some, and even completely for others. They also noticed that two patients on mechanical ventilation have been able to breathe on their own again, but with a high-flow nasal cannula and one patient needed no longer breathing support, just two days after the transfusion. Encouraging results that the study has compared with others involving patients in a similar state, but without plasma transfusion for a bigger contrast.

Encouraging results but not representative for now, as the Chinese scientific team explains in the article. But a way to relieve patients and the medical team from the sick influx. And a potential solution in a short-time period, while waiting for a vaccine to be developed. In France, a similar clinical trial of plasma transfusion from cured people is currently running, including 200 cured people and 60 Covid-19 patients. 

But this cure has limits, not on the effectiveness in patients, but its risky use as for the outbrea of variants. According to a study carried out by several scientists from the Cambridge University released in Nature, paired with Remdesivir, it could be at the origin of the mutations of the virus that led to those currently monitored, similar to the UK strain. Other studies are necessary to find out the exact limits of the transfusion's effectiveness.

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