The first UK patient has been treated in a reopened clinical trial that will look at whether blood from "super donors" can help fight Covid in people with weakened immune systems.
Super donors have high levels of antibodies that can be used to wipe out the virus in people with compromised immunity.
The Recovery and Remap-Cap trials found that convalescent blood from people who recovered from Covid did not benefit other patients.
The Remap-Cap trial was reopened to investigate whether donated blood with high levels of antibodies can save the lives of people with weakened immune systems.
The new trial is important because it is a group of patients who are still dying from Covid. It's something that could benefit them.
Those with certain immune disorders and people who are on medicines that suppress immune defences are vulnerable. In England, half a million people are immune suppressed.
More than 15 hospitals in the UK have agreed to participate in the trial. The first patient was transfused with blood.
The highest concentrations of antibodies with the broadest effectiveness against different Covid variants will come from patients who have been exposed to Covid and vaccined against it. There won't be a new appeal for donors because the donations will come from people who already gave blood.
A man in his 20s donated his blood to the trial. In the first wave of the Pandemic, his blood contained less than a thousand units of antibody per liter.
Estcourt said that if the trial finds that the blood product works, it would be a good treatment for people who don't respond to the vaccine or other therapies.
In the developing world, access to more expensive treatments is limited.