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Dr Gail Miflin

What does NHS Blood and Transplant do?

NHS Blood and Transplant (NHSBT) is the organisation responsible for the donation, manufacture, and supply of blood components to the NHS in England, and for the national donation and supply of organs. They supply around half the stem cells and tissues used by the NHS and carry out a range of research and provide specialist services to hospitals.

What is convalescent plasma?

Plasma is a yellow-coloured component of blood that is mostly water, but also contains enzymes, proteins, salts, sugars, fats and hormones. Convalescent plasma is collected from donors who have recovered from an illness (in this case, COVID-19) and contains antibodies against the disease-causing organism.

Through the rapid end-to end donation chain set up by NHS Blood and Transplant, COVID-19 patients were able to donate convalescent plasma for use in the RECOVERY trial.  (photo NHSBT)Through the rapid end-to end donation chain set up by NHS Blood and Transplant, COVID-19 patients were able to donate convalescent plasma for use in the RECOVERY trial. (photo NHSBT)

How did NHSBT become involved in the RECOVERY Trial?

At the start of the COVID-19 pandemic, when we had no treatments for this new disease, there was strong global interest in finding out whether convalescent plasma was effective, particularly as it was a technology that could be used in any setting. Various studies of convalescent plasma in COVID-19 patients were carried out worldwide, but these were too small to generate any conclusive answers. So towards the end of March 2020, Government advisors approached us to see if we could collect convalescent plasma at scale to support large randomised controlled trials. This led to a formal proposal which was approved and funded by the Department of Health and Social Care (DHSC). After rapidly building a complete end-to-end logistical chain, in April 2020 the first apheresis plasma donations were taken in April, 2020, (where a person’s blood is passed through an apparatus which removes a particular component, before returning the rest of the volume back to the body.) and the first patients were recruited to the convalescent plasma arm of RECOVERY in June 2020. 

Besides RECOVERY, we also collected convalescent plasma for the international REMAP-CAP trial.  

What happened to the convalescent plasma donations after they were collected?

Units of donated plasma were transported by NHSBT vehicles from the donation venue to the blood centre, where they were rapidly frozen and quarantined while screening took place. During screening, a sample from each unit underwent laboratory tests, including measuring the concentration of COVID-19 antibody levels, checking the ABO blood group, and testing for the presence of certain infectious, such as syphilis, hepatitis and HIV. Once these tests were complete, the donations were labelled and placed into controlled storage, ready to be sent to hospitals. Having the capacity for a rapid turnaround was very important, since the RECOVERY trial participants had to receive their first plasma transfusion within 48 hours of enrolling into the trial.

What were the main challenges of setting up a new collection system for convalescent plasma?

The first challenge was to rapidly set up an entirely new project with its own supply chain, while dealing with lockdowns and social distancing. This involved establishing a UK-wide network of donation centres and recruiting hundreds of new staff. At the peak of recruitment, we held 700 interviews in a six-week period! Due to the urgent time-frame and the need to socially distance, we switched from our standard 12-week face-to-face training programme to a six-week online-led model, using new simulation centres.

We also had the problem that we had no existing donor base, because we hadn’t specifically collected blood plasma for over 20 years. This meant we had to start entirely from scratch to identify suitable donors who we could reach out to. We put in place innovative data sharing agreements with NHS Digital and DHSC that gave us access to contact lists of individuals who had tested positive for COVID-19. This enabled us to identify large numbers of potential donors, who we then approached directly.

But we then discovered that less than 10% of plasma donors had the very high antibody levels needed. These people were typically patients recently hospitalised for COVID-19 (especially men), but the antibody levels only remained high for a few weeks. To reach this group who had high antibody levels, we focused our recruitment on regions with the greatest number of hospitalised patients. We worked with clinical staff to recruit potential donors while they were still in hospital, besides engaging primary care providers, religious organisations and community groups. In addition, we worked with high-profile partners (such as BT Sport) on targeted advertisement campaigns, and recruited celebrity ‘NHSBT Ambassadors ’, including Everton Football Club Manager Carlo Ancelotti.

What were the key highlights?


I think the numbers speak for themselves. Over 12 months, NHSBT set up more than 40 new clinics, including 21 brand new centres. Previously a new centre took over 18 months to set up.

We recruited and trained over 1,700 new colleagues, mostly at entry level, including for roles as healthcare assistants, nurses, call centre staff and manufacturing colleagues. We were proactive in recruiting staff and volunteers from non traditional and diverse backgrounds, for instance partnering with airlines such as EasyJet and the travel agency TUI to employ cabin crew to work shifts on their non-flying days, and to recruit volunteer staff on furlough. We also achieved a better diversity of collection staff, increasing the percentage of nurses from minority ethnic groups from 13% to 42%.

Meanwhile, our targeted communication strategy resulted in our plasma donor base growing from none in early 2020 to over 80,000 by March 2021. Of these, 82% had never donated blood before. At peak collection periods, we had up to 8,000 plasma donation appointments each week, and in total we collected over 90,000 units of plasma. This enabled the RECOVERY and REMAP-CAP trials to collectively randomise over 16,000 patients to test convalescent plasma.

At the same time, NHSBT provided laboratory equipment and samples for the COVID-19 testing programme, continued to support transplantation services in the NHS, and implemented Organ Donation Opt Out, the biggest change in organ donation legislation in our history, while maintaining our core job of supplying blood to hospitals.

Both RECOVERY and REMAP CAP concluded that, overall, convalescent plasma does not benefit hospitalised COVID-19 patients. Why was this result still important?

Thanks to NHSBT establishing the convalescent plasma donation chain so quickly, REMAP-CAP and RECOVERY were able to generate a clear result in real-time, while the pandemic was still ongoing.

In demonstrating for the first time that transfusing convalescent plasma into seriously ill COVID-19 patients was ineffective for the general patient population, these trials changed medical practice globally and allowed researchers to pivot to exploring other potential life-saving treatments.

What does the future hold for plasma treatments?

In February 2021, the Government lifted a restriction on the use of UK plasma to produce immunoglobulins, which are a type of plasma-derived medicinal product (PDMP). We are now using part of the new infrastructure and donor base for plasma collection to collect plasma from which immunoglobulins will be separated. These immunoglobulins will be used to treat NHS patients with a range of conditions, for instance disorders that cause a patient’s immune system to be compromised or over-active. Part of the unused stock of convalescent plasma may also be used to make PDMPs.

The UK’s immunoglobulin supply is currently completely dependent on plasma collected internationally, and there is an increasing global supply pressure. In pivoting the established supply chain for convalescent plasma to this new purpose, we will provide a lasting and important legacy that is a true testament to the dedication our workforce has shown throughout the pandemic.

There is also new evidence from the detailed analysis of subgroups within REMAP-CAP that shows plasma may benefit immunocompromised people when transfused earlier in the illness. We are supporting the re-opening of the plasma domain of REMAP-CAP on a smaller scale, taking new donations from people who have both had coronavirus and the vaccine.


The NHSBT team won a Royal College of Pathologists (RCPath) Achievement Award for ‘Significant Contribution to Speciality’ in November 2021. The awards celebrate excellence in pathology practice and promote high standards in pathology education, training and research to deliver the best patient care. The NHSBT team were commended for setting up research to test COVID convalescent plasma in the RECOVERY and REMAP-CAP trials. Read more on the RCPath website