Health officials have sent out a rallying call to Covid-19 survivors to donate their blood plasma.

Preliminary research suggests that three groups of patients have plasma which has the most potential to save lives. These include: patients over the age of 35, male Covid-19 survivors and patients who were ill enough to need hospital treatment.

A major trial is ongoing to assess whether convalescent plasma donations can be transfused into patients who are struggling to develop their own immune response.

The plasma from former patients is rich in the antibodies that develop as a person recovers from an illness.

It is transfused into people who are seriously ill with Covid-19 and struggling to develop their own antibodies.

If the trial is successful, being treated with convalescent plasma could become a widespread practice in hospitals.

NHS Blood and Transplant (NHSBT), which is collecting the plasma for the trial, said it is appealing to recovered Covid-19 patients, especially those who are male, over 35, or have been admitted to hospital, to come forward.

The move comes after the health body assessed plasma donations from 435 recovered Covid-19 patients.

The research found that men were twice as likely (34%) to have high enough antibody levels compared to women (17%).

And only 10% of people aged under 35 had high enough antibody levels compared to 31% of 35-to-45-year-olds and 40% of those aged over 45.

Former hospital patients had high levels of antibodies – 70% of those admitted to hospital had high enough antibody levels compared to 31% of donors who had a positive test for Covid-19 but who did not require hospital treatment.

The donor whose plasma had the highest antibody level of those measured so far is Alessandro Giardini.

The 46-year-old from Camden, London, was found to have an antibody level was around 40 times that of the typical convalescent plasma donation to NHSBT so far.

Dr Giardini, a consultant in the cardiology department of Great Ormond Street children’s hospital, spent seven days on a ventilator in intensive care after falling ill with Covid-19.

He said: “It was a very hard experience, not knowing if you will see your family again – I have two young children.

“I was aware of the convalescent plasma donation programme so I was expecting the call to come in and donate. I felt I had to give back.

“Even though it was scary to go back into a medical environment and have a needle again, I really felt that if there was any chance I could help someone else who was still ill with Covid-19, that I needed to do it.

“I felt great after donating plasma. It feels like we are in one interconnected community, helping each other. I was very much pleased and proud to have donated.”

Prof David Roberts, NHSBT’s associate medical director for blood donation, said: “These testing results mean we want hear from those who want to give convalescent plasma and especially want to hear people from men, the over-35s, and all people who needed hospital treatment.

“If you have recovered from a coronavirus infection, fall into any one of the these groups, and live near or could travel to one of our 23 donor centres, please contact us on 0300 123 23 23 or www.nhsbt.nhs.uk.

“These initial results are in line with past findings. People who are more seriously ill produce more antibodies, which can be transfused to potentially help others. The evidence so far is that men and older people are more seriously affected by coronavirus.

“Please help your NHS fight Covid-19. Convalescent plasma donation is safe and easy and you could save lives. If you get the call, please donate.”

– People who fall into one of the three categories are urged to contact NHSBT on 0300 123 23 23 or www.nhsbt.nhs.uk – they will also need to be able to travel to one of the 23 donor centres which are situated in: London, Manchester, Cambridge, Luton, Nottingham, Sheffield, Leicester, Bradford, Leeds, Newcastle, Lancaster, Liverpool, Stoke, Birmingham, Bristol, Gloucester, Oxford, Southampton, Poole and Plymouth.