Authorized on an experimental basis in France and the United States, serotherapy, that is to say the transfusion of blood plasma from patients cured of Covid-19 to patients hospitalized in serious condition, would show limited effectiveness.
- Tested on an experimental basis in the United States, the treatment of Covid-19 by blood plasma transfusion shows “limited efficacy” according to this new study.
- If the transfusion allowed an antiviral action against SARS-CoV-2, it did not reduce the number of serious forms or deaths from Covid-19.
This is not the miracle promised by Donald Trump. While last September, the American president ignited on serotherapy which could “save a considerable number of lives”a new study points to the low effectiveness of blood plasma in curing Covid-19.
Published in the medical journal BMJthis new work by Indian researchers concludes that “convalescent plasma has shown limited efficacy”.
Limited antiviral action
Used for the first time in 1892 against the bacillus responsible for diphtheria, then in 1918 to fight the Spanish flu, serotherapy consists of administering to Covid-19 patients blood plasma from patients who have recovered from the disease. Considered as “liquid gold” by some scientists, blood plasma contains a large number of antibodies which, injected in large numbers, would allow the patient to develop immune defenses capable of fighting the SARS-CoV-2 virus. This method has already proven itself to fight the Ebola virus or even SARS, which is from the same family as the new coronavirus.
However, this new study shows that blood plasma is not the miracle treatment expected to treat Covid-19. Funded by the Indian Council for Medical Research, the randomized study followed between April and July 464 patients with an average age of 52 years who were hospitalized. Of the two groups formed, the first of 229 patients received usual care, while the second received two transfusions of blood plasma from recovered patients. After a follow-up period of 28 days, 44 participants (or 19%) in the plasma group and 41 (or 18%) in the control group developed a severe form of the disease or died.
Limiting the comparison to patients who received plasma with a detectable level of antibodies, the results did not change. In contrast, plasma transfusions improved breathing difficulties and fatigue, and the virus was less often detectable after seven days. “The convalescent plasma did exactly what the researchers hoped for – a direct antiviral action of neutralizing antibodies on SARS-CoV-2 RNA – but there was no net clinical benefit for patients”report the authors of the study.
Results to put into perspective
If it’s a trial “rigorous”, as Elizabeth Pathak, public health specialist, points out in the BMJ, the results must however be put into perspective. Thus, the National Health Service, the British health service, which also conducts research on blood plasma, points out that the authors of the study used plasma donations containing between 6 and 10 times less antibodies than those collected in the UK. “There are other promising indications that convalescent plasma with high levels of antibodies could improve patient outcomes”he believes.
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