According to the results of a large study, administering plasma obtained from convalescents to patients with severe Covid-19 does not change the course of the disease
The results of a branch of Remap-Cap (Randomised, Embedded, Multifactorial, Adaptive Platform Trial for Community-Acquired Pneumonia), a major clinical study involving thousands of patients all over the world, they seem to put an end to resorting to plasma iperimmune for the treatment of patients with Covid-19 grave: in most cases it is useless.
The use of hyperimmune plasma, the authors of the article published on the pages of Jama, he had his why at the start of the pandemic: next to nothing was known about the novel coronavirus, and the available treatment alternatives were gods too attempts. Furthermore, the administration of plasma from convalescent patients had demonstrated a certain effectiveness to change the course of other viral diseases, for example Ebola.
The actual effectiveness of the hyperimmune plasma for Covid-19, however, remained doubtful for a while’. The problem – recalls Bryan McVerry, an expert at the University of Pittsburgh Medical Center who participated in the research – was that in the chaos of the emergency, with thousands of sick people and no standard of care, the therapy was administered. outside of clinical trials, therefore without real patient selection criteria (not all of them were in critical condition) nor a real control population. “With these results today we can put an end to the use of hyperimmune plasma in patients with severe Covid-19 and focus on the treatments that we know work, as well as on the development and testing of better treatments “, McVerry points out.
In fact, from Remap-Cap it emerged that after the infusion of two units of hyperimmune plasma to critical Covid patients there were no substantial differences in progression of the disease compared to what happened in patients in the same conditions but who had received standard care. In particular, there was no difference in the probability of survival at at least three weeks without the need for respiratory support.
The researchers say they are almost certain of the uselessness of hyperimmune plasma in severely ill patients. However, the data showed that in immunocompromised patients hyperimmune plasma administration appears to have a slight benefit compared to standard care. The number however is too small (126 patients only) in order to draw conclusions. “It could be that patients with a compromised immune system, who are unable to develop an effective immune response, may still benefit from the antibodies present in the blood plasma of patients recovered from Covid, especially at the beginning of the disease”, comments Lise Estcourt, of the University of Oxford and director of the Unit for Clinical Blood and Transplant Trials of the UK’s National Health Service. “This is a given definitely deserves an investigation“.
Ma because hyperimmune plasma not working? Scientists cannot give an answer. Maybe there are too many few “quality” antibodies, or the patients are now in conditions too critical because they can make a difference and slow down progression.
In fact, it is not correct to say that the strategy does not work in general: it is possible that the hyperimmune plasma has an effect on patients who are in better conditions, again at the beginning of the infection. But in these cases, today, it is perhaps preferable to use monoclonal antibodies, because they are more efficient.