"Covid hit me like a steam train," recalled Twickenham postal manager Stephen Craib who is urging fellow coronavirus patients to give plasma to help derail the virus.

Stephen was taken ill in March. He'd been cycling earlier in the day but "woke up sweating buckets".

But he is now back on track and has made 16 donations of plasma for research to see if it can treat other coronavirus patients.

The donations are needed for NHS Blood and Transplant's (NHSBT) collaborations with the recovery and remap-cap trials, which will provide answers on whether plasma is an effective treatment for Covid-19.

People who were hospitalised have higher levels of antibodies and the NHSBT is keen to recruit them in their urgent quest for treatments.

Men were particularly hit hard by the virus along with BAME patients and body is appealing to them to join the project, along with the over 35s. But they stressed they want to hear from anyone who had covid.

By the beginning of November, 10,200 units of plasma were donated – with 217 from men who were hospitalised by covid.

There are donation centres across London.

Stephen said: "It does not hurt and it's normally an hour from start to finish. I would say do it.

"The NHS has done so much for me over the years, this is a way to give back.

"The donation process is lovely really, because of the staff. To me, the question is why wouldn't I do it, if I have the antibodies to help someone else."

He is relishing being busy back at work where he's not had time to think about the new covid vaccine. "It's been Christmas 2.0 every day," he said.

Back in the spring it was a different story.

He recalled feeling "absolutely freezing cold" and in hindsight realised that his sense of taste was affected meant the pizza he cooked "did not taste like a pepperoni pizza".

The 42-year-old father of two was checked out at hospital but his oxygen levels were not causing concern.

Mr Craib spent the next week being cared for by his sister Angie Hennessy and recalled feeling so exhausted "even sitting up in bed was an effort, it took me 20 minutes to get the energy".

As his condition deteriorated he was admitted to St Helier Hospital in Epsom, south London.

He was one of their first coronavirus patients and recalled: "It was a very weird time. I was in a four bed ward for four days on my own. The hardest part was the loneliness."

Coronavirus is a respiratory illness and Mr Craib had pneumonia while he was ill.

And the illness hit hard. "I felt like I was dying," he said.

Staff had to wear full protective gear and visitors were not allowed for fear of infection.

It was his daughter Lily's 15th birthday whilst he was in hospital, which was tough for all the family.

But he was able to return to work a month later at Twickenham postal centre where he manages 65 postal workers and has also resumed cycling with his friends. He still notices that it is harder to get oxygen when tackling tougher routes.

"I can feel the effort it is now."

Mr Craib signed up to the plasma donor scheme so scientists can discover if plasma could help in the battle against covid-19.

And he is urging other people who had covid to join in too.

"Give the NHS a Christmas present.

"Don't worry about it. All the staff have been great, it's a pleasant experience. It's only an hour out of your day. It's so clean and well run."

Lise Estcourt is head of the NHSBT Clinical Trials Unit. She said: "The latest analysis shows people who had hospital care make our best donors. They have the highest antibody levels and their antibodies stay higher for longer.

"We understand some people who've had hospital care might be nervous coming back into an environment with a medical atmosphere. Our teams are specially trained to make people feel welcome and many donors tell us the staff are the best part about donating.

"We can reassure people that donation does not affect how your antibody levels change over time. Your body quickly replaces the donated plasma and antibodies and it does not affect antibody levels in the long term. By donating, you could save lives."

Where you can donate

Coronavirus patients have been contacted about the trial. To get involved, register here.

• Blood donor centres which can now take plasma – Birmingham, Bradford, Bristol, Cambridge, Edgware, Gloucester, Lancaster, Leeds City Centre, Leicester, Liverpool, Luton, Manchester Norfolk House, Manchester Plymouth Grove, Newcastle, Nottingham, Oxford, Plymouth, Poole, Sheffield, Southampton, Stoke, Tooting, London West End
• Plasma donation pop-up centres opened earlier this year – Liverpool Speke, Leeds Seacroft, Stratford, Bexleyheath, Twickenham
• Pop-up centres opening this winter – Arundel, Ashford, Barnsley, Bolton, Coventry, Croydon, Huddersfield, Northampton, Reading, Scunthorpe, Stockton-On-Tees, Tottenham, Woking, Wolverhampton