Five coronavirus patients in critical condition have tested negative in the space of 12 days after receiving treatment with recovered patients' blood in China.

Three of them have been discharged from the hospital while the others are in stable condition, according to a report from the hospital on Friday.

A doctor leading the treatment believed these successful cases could 'bring hopes to more coronavirus patients'.

The news comes as pressure is growing on the UK to use a promising therapy for critically ill coronavirus patients after the US approved the blood-based therapy last week.

Blood plasma from former patients contains antibodies that are purposely developed by their immune systems to fight the virus. Pictured: Vials of blood being tested for infection

Blood plasma from cured patients contains antibodies that are purposely developed by their immune systems to fight the virus.

Scientists believe the method, known as convalescent plasma, could treat the sickest patients by bolster their immune systems, using blood from recovered donors.

The Shenzhen Third People's Hospital published a medical paper on March 27, documenting the treatment process of the five patients, aged 36 to 73.

The hospital, which has the National Clinical Research Centre for Infectious Disease, said four of them showed normal temperatures within three days after being treated with blood from five donors.

All patients, including three men and two women, tested negative after 12-day treatment and the antibodies in their immune systems 'significantly boosted', said the hospital.

Scientists believe the method, known as convalescent plasma, could treat the sickest patients by transferring recovered donors' blood to bolster their immune systems. A cured coronavirus patient has his condition checked at an outpatient department at a Guangdong hospital

All patients, including three men and two women, tested negative after 12-day treatment and the antibodies in their immune systems 'significantly boosted', said the hospital. A recovered COVID-19 patient donates his blood plasma in Wuhan of central China's Hubei Province

'We first started using recovered patients' blood plasma to treat our critically ill patients on January 30,' Liu Yingxia, deputy director of the hospital, told Pear Video.

'We hope sharing our research could provide first-hand clinical experience for international medical workers and bring hopes to more coronavirus patients.'

Hospitals around China have been widely using the blood-based method to treat their patients - but the UK has still yet to even test the treatment.

Leading British scientists say the therapy could 'make a life or death difference' for patients in the most critical states and that doctors should 'definitely' try it.

The method may be the best hope for COVID-19 patients while scientists work to develop new, specific treatments for the disease.

And researchers say it could work as a temporary shield for the most vulnerable by protecting them if they catch the virus, almost like a vaccine.

The news comes as pressure is growing on the UK to use a promising therapy for critically ill coronavirus patients after the US approved the blood-based therapy last week. Residents are pictured shopping in Milwaukee, Wisconsin, a hotspot for the coronavirus in the US

Leading scientists have now called for the 'promising' treatment to be used in the UK, where over 22,000 people have been infected and 1,408 have died. Chinese medics are pictured working in a laboratory in Guangzhou, Guangdong Province on February 19

Dr.Mike Ryan, head of WHO's health emergencies program, said using convalescent plasma was a 'very valid' approach.

He said: 'It must be given at the right time because it mops up the virus in the system, and it just gives the new patient's immune system a vital push at the time it needs it. But it has to be carefully timed and it's not always successful.'

Leading scientists have now called for the 'promising' treatment to be used in the UK, where over 22,000 people have been infected and 1,408 have died.

Researchers around the world are scrambling to find a cure for the killer virus, with dozens of drugs being tested.

Earlier this month, China launched its first clinical trial for coronavirus vaccine developed by the country's top military bio-warfare expert and her team.

'Vaccine is the strongest scientific weapon to end the coronavirus,' the bio-warfare expert, Chen Wei, told state broadcaster CCTV.

The research team also prepared for large-scale production of the vaccine, Chen added.

More than 785,000 people around the world have now caught the coronavirus, with 37,703 patients known to have died since the outbreak began in December.