The concept of convalescent plasma therapy for COVID-19 has made its way into Telangana. It is expected that the plasma collected from recovered patients will contain antibodies which neutralises the virus, and that would be infused into active patients.
The mortality rate could be brought down when the plasma filled with neutralising antibodies are infused into critically ill patients. Given that there are no vaccines to prevent the disease or an antiviral to treat it, convalescent plasma therapy is being considered an option.
Its effectiveness as a treatment option, however, is yet to be proved. Virologists have called for research into various aspects of the treatment, which has been taken up in different parts of the world. If successful, it will help improve chances of survival of critically-ill patients.
Municipal Administration and Urban Development Minister K.T. Rama Rao tweeted that Biocon Limited executive chairperson Kiran Mazumdar Shaw has suggested setting up a ‘COVID blood bank’ in Telangana, where antibody-rich plasma from people who have recovered from the infectious disease is collected. He has directed Health officials to explore it further. Special Chief Secretary of Health department A. Santhi Kumari said they will not leave any stone unturned in this respect.
Dates back to 1918
This is not the first time the therapy will be used against an infectious disease. Convalescent plasma as a treatment option dates back to 1918 when it was used in treatment of H1N1 influenza.
While plasma is the liquid portion of blood collected before clotting, serum is the fluid part collected after clotting. Virologists have said that both contains antibodies.
Sunit K. Singh, professor of Molecular Immunology and Virology, Institute of Medical Sciences, Banaras Hindu University, said that the first task is to find virus neutralising antibodies. “Then plasma or serum containing the neutralising antibodies have to be given to critically-ill patients. Premise of the theory is that the infused antibodies acts against the virus in active patients (receiver). But we need to know how long the neutralising effect of antibodies will last; whether it will be for a week, a month or more. Research into this is required and also to find the effectiveness of the treatment,” Dr Singh said.
The next task is to select a donor which depends on the ‘titer’ amount. Titer is number of antibodies present in a given amount of plasma or serum. The higher the better. “We need to find out at which stage of the infection the antibodies have to be infused; whether at 14 days of contracting the virus or other time,” he said.
Secretary (Medical Virology) of Indian Virological Society, Shailendra K. Saxena said that care needs to be taken to ensure plasma does not contain any copies of coronavirus. “There is scope for a lot of research. Plasma collected from the people who have recovered from COVID-19 can be stored and studied which will help us to know the therapeutic use of convalescent plasma. This has to be explored,” Prof Saxena said.
He added that another option is to isolate the antibodies and enhance their numbers which can be infused into patients.
Virologists have also stressed the need to ensure that plasma from donors does not contain any pathogen.