Wales is playing a leading role in the UK programme for treating coronavirus patients using a blood donation extract taken from people who have recovered from COVID-19.
Non COVID-19 plasma has been used daily in NHS Wales for a variety of needs for many years.
COVID19 "convalescent plasma" will help patients develop immunity as it 'transfuses' antibodies against the virus, helping the receiving individual fight infection.
Recovered patients are being invited by letter, if eligible, to donate blood to the scheme.
The Welsh Blood Service, Welsh Government, Public Health Wales and University Hospital of Wales are now working with partners across the UK to share knowledge, procedures, best practice and learning.
The programme will capture the benefit of plasma transfusions to improve COVID-19 patients' speed of recovery and survival.
In Wales, the plasma collected will be made available to clinicians for the benefit of COVID-19 patients, for example through participation in clinical trials which will inform the best possible future use.
Public Health Wales will identify and write to potential donors who have a confirmed COVID-19 positive test result and are eligible.
The plasma will be collected and processed by the Welsh Blood Service.
The Welsh Government says donor safety and wellbeing are paramount, and donors must be fully recovered before donating and virus free. For these reasons, normally, plasma will be collected no sooner than 28 days after recovery and the established safe blood donor selection criteria.
Senior Professional Advisor to Chief Medical Officer, Dr Gill Richardson, said: "Convalescent plasma is plasma that is collected from patients who have recovered from disease, in this case COVID-19.
"Plasma from patients who have recovered from the virus will contain antibodies that a patient's immune system has produced to fight the virus. This can be transfused to patients whose immune systems are struggling to develop their own antibodies.
"The Welsh Government has worked at speed with our expert scientists at the Welsh Blood Service, the Department of Immunology at University Hospital of Wales, Critical Care Consultants and Public Health Wales to launch this innovative scheme.
"In the absence of any current vaccine or antiviral therapy, it has significant potential to aid the recovery of patients."