Plasma therapy as a treatment for COVID 19 is being tested throughout the world. It is still in experimental phase. India is approaching it with caution. In fact Ministry of Health has still not approved it as a treatment and issued a statement that ICMR is still studying its efficacy through a national level study.
Few days ago, AIIMS Director had confirmed that the All India Institute of Medical Sciences is planning to conduct a clinical trial of the convalescent plasma therapy in the treatment of COVID-19 patients. In fact, Ministry’s statement comes days after Drug Controller-General of India gave its go-ahead to a proposal by the ICMR for the clinical trial of convalescent plasma therapy in COVID-19 patients as per the protocol developed by ICMR.
Plasma therapy uses plasma of recovered patients so that its antibodies can detect the virus and mitigate its growth.
For the therapy to be effective it must contain sufficient amount of neutralizing antibody. It has been used earlier with varying success in previous viral epidemics SARS-CoV1 and MERS and also in H1N1.
Meanwhile Health Minister of Maharashtra has confirmed that first plasma therapy has been successful in Mumbai’s Lilavati hospital and another experiment is underway on patient in BYL Nair hospital.
However this therapy is not without risks and there are hazards like inadvertent transfer of blood borne infections and immunological reactions. The government is being careful since some of these risks can be serious and include transfusion-related acute lung injury (TRALI) which can cause breathing difficulty/respiratory failure, transfusion-associated circulatory overload (TACO) which can cause heart failure symptoms, allergic reactions or life-threatening anaphylactic shock, risk of infection from other pathogens in the donor’s plasma or acquired during processing, fever, graft vs host disease, hemolysis or breakdown of red blood cells in the recipient etc.
Meanwhile UK government has approved a national clinical trial to assess plasma therapy for treatment. England deputy chief medical officer Jonathan Van Tam said: “The UK is leading the world’s largest trials to find a treatment for Covid-19, with over 7,000 people so far involved testing a range of medicines. We hope to add convalescent plasma to this list shortly.” The government is also scaling up the national plasma collection programme to enable broad availability of the treatment if it is found to be effective. Over April and May, the plasma collection will be increased to reach up to 10,000 units per week to the NHS.
In the US, which has seen a huge surge in cases, FDA has issued guidance to provide recommendations to health care providers and investigators on the administration and study of investigational convalescent plasma collected from individuals who have recovered from COVID-19. It is being regulated as an investigational product.
There are only a handful of studies that have evaluated the effectiveness of plasma therapy. Article in Journal of Medical Virology looks at treatment of six confirmed COVID patients in Wuhan, China, using ABO‐compatible convalescent plasma and evaluated efficacy of this treatment by the alleviation of symptoms, changes in radiologic abnormalities and laboratory tests. No adverse effects were observed and in two patients elimination of virus was seen. Serological analysis indicated an immediate increase in anti SARS-CoV-2 antibody in two other patients. The study concludes that the therapy shows promise.
Another study by National Academy of Sciences of the United States of America studied 10 severe adult cases and showed that no adverse effects were observed and that CP therapy was well tolerated and could potentially improve the clinical outcomes through neutralizing viremia in severe COVID-19 cases. However the study noted that optimal dose and time point, as well as the clinical benefit of CP therapy, needed further investigation in larger well-controlled trials.
Paper in The Lancet reviews several studies on the effectiveness of plasma therapy for H1N1 but notes that randomized clinical trials are needed to evaluate the safety and efficacy of plasma therapy in treatment of COVID 19.
Plasma therapy for treatment of COVID 19 shows overall promise. With development of vaccination for prevention and plasma therapy for treatment, COVID 19 may be finally brought under control.