Doctors have drawn up plans to infuse British coronavirus patients and their carers with blood plasma harvested from “hyperimmune” people who have recovered from the infection in an attempt to save lives.

The experimental treatment will be directed at patients who are admitted to hospital with pneumonia caused by the virus in the hope that it reduces the number who end up on ventilators in intensive care units (ICUs).

Those in close contact with Covid-19 patients, such as NHS staff and family members, are also in line to be offered the treatment in an effort to stem the spread of the illness and further reduce pressure on the health service.

The procedure relies on the fact that people who have recovered from Covid-19 have antibodies in their blood plasma that maintain a defence against the infection. The aim is to identify those who are “hyperimmune” to the virus and invite them to donate blood for the treatment.

So-called “convalescent plasma” would be given to patients and their contacts in a number of clinical trials that are under consideration with medical funding bodies.

Prof David Tappin, a senior research fellow at the University of Glasgow, has applied to the National Institute for Health Research to run two clinical trials with convalescent plasma.

“Start-up will need to be faster than is normal, with most other trials usually taking months or years to get approvals and to begin,” he said.

Q&A How can I protect myself and others from the coronavirus outbreak? Show Hide The World Health Organization is recommending that people take simple precautions to reduce exposure to and transmission of the coronavirus, for which there is no specific cure or vaccine. The UN agency advises people to: Frequently wash their hands with an alcohol-based hand rub or warm water and soap

Cover their mouth and nose with a flexed elbow or tissue when sneezing or coughing

Avoid close contact with anyone who has a fever or cough

Seek early medical help if they have a fever, cough and difficulty breathing, and share their travel history with healthcare providers

Advice about face masks varies. Wearing them while out and about may offer some protection against both spreading and catching the virus via coughs and sneezes, but it is not a cast-iron guarantee of protection Many countries are now enforcing or recommending curfews or lockdowns. Check with your local authorities for up-to-date information about the situation in your area. In the UK, NHS advice is that anyone with symptoms should stay at home for at least 7 days. If you live with other people, they should stay at home for at least 14 days, to avoid spreading the infection outside the home.

The trials will look for evidence that convalescent plasma can reduce infections in carers so they can continue their work, prevent patients deteriorating to the point that they require ventilation in ICUs, and improve the condition of those who are already severely ill, to reduce deaths and free up the much-needed ventilators, he said.

“Trials need to be undertaken, otherwise we will not know if this intervention is effective and worthwhile,” Tappin said. “It may not be a silver bullet, or it may work for instance to stem the development of Covid-19 infection in contacts such as healthcare workers and their families, but not perhaps be as effective to treat severely ill patients being ventilated.”

Prof Robert Lechler, the president of the Academy of Medical Sciences and executive director of King’s Health Partners, comprising King’s College London and three major London hospitals, said the group intended to conduct parallel trials of convalescent plasma.

NHS Blood and Transplant has already begun work to identify potential donors, a spokesperson said.

“Plasma from patients who have recovered from Covid-19 will contain antibodies that their immune systems have produced in fighting the virus. That plasma can be transfused to very poorly patients whose own immune systems are struggling to develop their own antibodies. The plasma transfusion is therefore intended to provide the poorly patient with antibodies from a recovered patient to help their body fight the Covid-19 virus.”

Quick guide What to do if you have coronavirus symptoms in the UK Show Hide Symptoms are defined by the NHS as either: a high temperature - you feel hot to touch on your chest or back

a new continuous cough - this means you've started coughing repeatedly NHS advice is that anyone with symptoms should stay at home for at least 7 days.

If you live with other people, they should stay at home for at least 14 days, to avoid spreading the infection outside the home. After 14 days, anyone you live with who does not have symptoms can return to their normal routine. But, if anyone in your home gets symptoms, they should stay at home for 7 days from the day their symptoms start. Even if it means they're at home for longer than 14 days. If you live with someone who is 70 or over, has a long-term condition, is pregnant or has a weakened immune system, try to find somewhere else for them to stay for 14 days. If you have to stay at home together, try to keep away from each other as much as possible. After 7 days, if you no longer have a high temperature you can return to your normal routine. If you still have a high temperature, stay at home until your temperature returns to normal. If you still have a cough after 7 days, but your temperature is normal, you do not need to continue staying at home. A cough can last for several weeks after the infection has gone.

Staying at home means you should: not go to work, school or public areas

not use public transport or taxis

not have visitors, such as friends and family, in your home

not go out to buy food or collect medicine – order them by phone or online, or ask someone else to drop them off at your home You can use your garden, if you have one. You can also leave the house to exercise – but stay at least 2 metres away from other people. If you have symptoms of coronavirus, use the NHS 111 coronavirus service to find out what to do. Source: NHS England on 23 March 2020

The blood products will be screened to ensure they are safe to transfuse.

The UK effort has been fuelled by a grassroots collaboration in the US in which 100 laboratories have joined forces to produce convalescent plasma for patients pouring into hospitals across the country. After receiving approval from the Food and Drug Administration, doctors in the US are now able to give plasma to patients under compassionate use rules.

Prof Arturo Casadevall, an infectious disease specialist at Johns Hopkins University in Baltimore, Maryland, who is involved in the US effort, said infusions of antibodies may be more effective if they are given early on to wipe out the virus before it causes serious damage. Potentially, he said, an infusion of convalescent plasma could protect people from the virus for several weeks.

On Friday, Chinese researchers reported that convalescent plasma appeared to help Covid-19 patients on ventilation, but the study involved only five patients.

Casadevall has shared the US procedures with Tappin and Lechler to help them develop the procedure in the UK. “I said, the best thing you can do is try and establish a network in the UK because ultimately all this is going to have to be done locally,” he said.

“If you look at history, this has a good chance of working. But it is a new virus and with a new virus you don’t know until you know. The Chinese have been using it and they are reporting good results, but it needs to be tested. This is not a panacea or a miracle cure; it’s something to try and put in place to see if we can help stem the epidemic,” he said. “I think you are going to need it in the UK.”