Dubai: In the absence of a vaccine or cure for coronavirus, can the blood or plasma of people who have recovered from the disease be used to treat other patients?
Dr. Farida Al Hosani, official spokesperson for the UAE health sector, said on Saturday that it was one of many treatment methods being used, while UAE doctors say once a person has recovered they have developed antibodies that will stay in their blood to fight the same virus.
“Those antibodies, when injected into another person with the disease, will recognise the virus as something to attack,” said Dr Faisal Asad, consultant pulmonologist at Saudi German Hospital.
This treatment is called convalescent plasma therapy.
Plasma, which contains water, salts, enzymes, antibodies and other proteins, is the single largest component of human blood.
It is the clear, liquid portion of blood that remains after red blood cells, white blood cells, platelets and other cellular components are removed.
Doctors believe the plasma of patients who have completely recovered from COVID-19 is rich in antibodies.
Dr Asad said, “The blood plasma obtained from patients recovered from infectious illnesses containing antibodies is used to treat patients who have not yet developed antibodies in their own body.
“In the past it has shown success in cases like diphtheria and the Ebola virus. The concept is to buy prepared food when one is very hungry and has no time to cook by oneself. Patients who are critically-ill and do not respond to other treatments are considered for such treatment as per set protocols,” he added.
Although large-scale scientific studies are not yet available, this approach can be very useful in treatment of critically-ill COVID-19 patients, said another doctor.
Dr. Suneet Kaur, Specialist Pathology and Hospital Oupatient Doctor at NMC Specialty Hospital Al Ain, explained: “Donor antibodies may potentially help patients (those on ventilators, old people, or people with poor immunity) to fight off the disease in a more effective way by providing them with passive immunity. These passive antibodies last for short periods of time like weeks or months.”
Dr Kaur reiterated convalescent plasma therapy has been used in the past, even for measles and mumps before vaccines were developed for them.
The U.S. Food and Drug Administration has also approved the use of convalescent serum in the treatment of Covid-19 patients under compassionate use, she added.
Plasma transfusion done in some countries
Dr. Muhammed Anas Ayoob, specialist Pulmonary Disease at NMC Specialty Hospital-Abu Dhabi, said blood plasma transfusion is already being done in China, France, Philippines, USA and other countries.
“The immunoglobulins, also known as antibodies, are used to neutralise the pathogens especially the viral or bacterial pathogens. These antibodies could help to the fight the virus, particularly in the acute stage of the disease or in the critically-ill patients,” he said.
“The good thing is results are better in China and we are waiting for the other reports, including in New York and Texas, to come out soon. We are all hoping for good results and better medicine against coronavirus,” he added.
Dr Sunil Kumar Garg, specialist Critical Care at NMC Royal Hospital-DIP, for his part, added: “With a vaccine likely months to a year away, scientists hope that convalescent plasma therapy can help those sickest with the virus now. Researchers hope that convalescent plasma will be effective in treating people with the most severe symptoms of the virus. Additionally, it is hoped that it can keep those people who are not as sick from COVID-19 from getting any sicker.”
Dr. Abinash Sher Inder Singh Paul, specialist respiratory medicine at Burjeel Royal Hospital Al Ain, meanwhile, pointed out that COVID-19 is a new pathogen.
“Safety concerns when any blood product is being used will have to be dealt with. But in the absence of any specific treatment, using convalescent sera to provide immunity to those critically ill may hold some promise,” D. Abinash told Gulf News.
“It has already been used for rabies prevention, in tetanus cases and in snake bite. It is not a novel idea. The pool of recovered cases is growing and availability of convalescent sera is not likely to be an issue,” he added.
Dr Sundar Elayaperumal, specialist microbiologist from Burjeel Hospital and member of the American Society of Microbiology, also said: “Potential hazards of transmitting other blood borne pathogens (eg. HIV) cannot be ruled out if the plasma is not properly screened for these pathogens.”
“(But) it doesn’t mean that passive antibody therapy wouldn’t help someone critically-ill with COVID-19. The antibodies may prevent the virus from expanding its numbers,” he added.
“Clinical trials of convalescent plasma have begun in some countries. As doctors await answers from completed trials, patients may receive the treatment under the FDA’s emergency authorization (EAU),” Dr Sundar noted.
Who can donate blood for COVID-19 therapy?
According to doctors, convalescent plasma therapy is a voluntary blood donation from patients who have recovered from COVID-19. Swab samples will be done three times before blood will be collected and tested for HIV, Hepatitis and other procedures and only then, plasma would be taken from the blood of recovered patients.
A person who can donate blood must be:
- At least 17 years old and weigh at least 110 lbs.
- In good health and feeling well.
- Have a prior diagnosis of COVID-19 and meet specific laboratory criteria.
- Be symptom-free for at least 14 days prior to donation.