January 13, 2021

expert reaction to study looking at convalescent plasma antibody levels and risk of death from COVID-19

A study published in the New England Journal of Medicine (NEJM) looks at convalescent plasma antibody levels and the risk of death from COVID-19.

Dr Lise Estcourt, Head of NHSBT’s Clinical Trials Unit, said:

“This new paper reports additional analyses from the Expanded Access Programme in the USA.  It is encouraging to see that the results suggest that high titre convalescent plasma reduces death from COVID-19 in patients who don’t yet require intensive care support for their breathing.  The world’s largest convalescent plasma trial, the RECOVERY trial, will be able to tell us whether this finding is true.  We hope that the results of this trial will be available in the next few weeks.”

Please note that at the time of writing this comment only the abstract of the paper was available:

Prof Stephen Evans, Professor of Pharmacoepidemiology, London School of Hygiene & Tropical Medicine, said:

“This abstract (the full paper is not available yet) gives summary information on an observational study of convalescent plasma in patients.

“A registry of patients receiving such plasma by transfusion was set up and the levels of antibodies in the plasma were measured.

“They were classified into three groups with high, medium and low levels of antibody.

“This is not the same as a randomised trial.

“There was a trend towards improved mortality the higher the level, with high levels having a mortality of about 22.3% and low levels about 29.6%.  This trend was only seen in those who had not had mechanical ventilation before transfusion.

“This is some evidence but it is quite weak for a beneficial effect of convalescent plasma but the effects are not dramatic.  Evidence from randomised trials will be more reliable.”

‘Convalescent plasma antibody levels and the risk of death from Covid-19’ by M. J. Joyner et al. was published in the New England Journal of Medicine at 22:00 UK time on Wednesday 13 January 2021.

DOI: 10.1056/NEJMoa2031893

Declared interests

Dr Lise Estcourt: “Lise is one of the donation and transfusion clinical leads for NHSBT’s work with the plasma arms of the RECOVERY and REMAP-CAP trials.”

Prof Stephen Evans: “No conflicts of interest.  I am funded (one day per week) by LSHTM.  They get funding from various companies, including Astra Zeneca and GSK but I am not funded by them, I have no involvement in obtaining funding from them and I am not an investigator on any grants obtained from them.  I am the statistician to the ‘meta-Data Safety and Monitoring Board’ for CEPI.  I am paid for my attendance at those meetings and will be paid expenses for travel if that occurs.  I am a participant in the Oxford/Astra Zeneca trial, but am still “blind” to the vaccine received.”