Convalescent plasma trials

We have been collecting plasma for clinical research into treatments for COVID-19.

A donor carer checks a donor's veins
Male donors who were very unwell with coronavirus are proving to have the highest levels of antibodies

Convalescent plasma is the liquid part of blood taken from people who have recovered from COVID-19. This plasma may contain antibodies that their immune systems have produced in fighting the virus. These neutralising antibodies stop the virus getting into cells.

There is some evidence globally that COVID-19 patients may benefit from being given convalescent plasma. However, the safety and effectiveness of convalescent plasma transfusions needed to be confirmed by robust clinical trials.

Treatment trials have taken place to establish whether a range of potential treatments, including COVID-19 convalescent plasma, benefit patients and at what point in their illness they should be treated.

The NHSBT Clinical Trials Unit was responsible for the management of the convalescent plasma aspects of two trials - REMAP-CAP and RECOVERY.

The REMAP-CAP trial

The REMAP-CAP trial was an international trial into the best range of treatments for people with COVID-19. It was an adaptive trial which meant different treatments could be added over time and patients could receive different treatments. 

The convalescent plasma treatment in this trial was for people who had been in intensive care for less than 48 hours and have tested positive for COVID-19.

People who received plasma as part of their treatment had two transfusions over two days and were monitored for 21 days to see how effective this was.

The trial paused enrolment for patients in intensive care in January 2021 and began to analyse the data.

Initial analysis of all trial patients requiring intensive care unit support showed that convalescent plasma did not improve outcomes. 

Work is underway to explore whether subgroups of people in intensive care benefit from plasma. The final results are not yet known.

The REMAP-CAP trial in intensive care patients was jointly led by:

  • Dr Lise Estcourt and Prof David Roberts - NHSBT Clinical Trials Unit and University of Oxford
  • Prof David Menon - University of Cambridge
  • Dr Manu Shankar Hari - Guy’s and St Thomas’ Hospital NHS Foundation Trust and King's College London

Visit theREMAP-CAP trial websiteto find out more.

Plasma bag
A bag of donated plasma

The RECOVERY trial

The RECOVERY trial compared different treatments that may be useful for people with COVID-19.

In this trial, we worked on the effectiveness of convalescent plasma for treating patients with COVID-19 who are in hospital, but not in intensive care.

The RECOVERY trial asked hospitals to stop randomisations of patients into convalescent plasma on 15 January 2021.

The interim results did not show evidence that convalescent plasma has an overall benefit on patient outcomes in moderately ill people. 

The trial is continuing to collect follow up information and carry out analysis to see if there is evidence of benefit in a subgroup.

The RECOVERY trial is led by:

  • Prof Peter Horby - University of Oxford
  • Dr Lise Estcourt and Prof David Roberts - NHSBT Clinical Trials Unit and University of Oxford

Visit the RECOVERY trial website for more information.

Donor holding plasma bag
Donors have given thousands of units of plasma for the trials


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