COVID-19 will probably be a part of our lives for the foreseeable future. A vaccine has yet to materialize. As the pandemic continues to take a crushing toll, doctors are resorting to a century-old treatment that has been helpful in managing previous pandemics: taking antibodies from those who have recovered and giving it to the sick. It’s known as convalescent plasma therapy, or survivors’ blood.
Plasma
- Plasma – the liquid component of blood contains antibodies. Plasma helps circulate proteins, nutrients and hormones throughout the body.
- Blood is made of four main components. Red blood cells carry oxygen around the body, white blood cells support immune function, and cell fragments called platelets form clots to stop bleeding. The liquid portion is plasma and comprises a little more than 50% of blood volume.
Features of Convalescent Plasma Therapy
- Extracting plasma from someone that has convalesced, or recovered, from an illness might provide a much-needed boost to the immune system of someone grappling with coronavirus.
- In the past, plasma therapy has been a weapon against the 1918 flu, polio, measles, rabies, hepatitis B and Ebola with varying levels of success.
- More recently, it showed some promise in treating other coronaviruses like SARS and MERS, particularly when given to a patient early in their illness.
- A dose of antibodies doesn’t directly stimulate a person’s immune system to start creating their own antibodies, but it does offer some protection until their own immune system ramps up.
- Scientists are interested in plasma as a COVID-19 treatment because the substance contains antibodies after an infection. These protective proteins can bind to the surface of an antigen, or a foreign invader, and help the immune system dismantle it.
- Ultimately, plasma therapy might shorten the length of illness and reduce the severity of the disease.
- Further, plasma therapy is not a vaccine. Vaccines use the immune system’s memory response to train it to detect and respond to specific pathogens.
Plasma Therapy for COVID-19
- The serum of COVID-19 cured individuals will have virus neutralising antibodies which will act as a passive antibody therapy.
- Convalescent plasma CP therapy failed to benefit COVID-19 patients, the largest trial conducted across 39 hospitals in India and spearheaded by the Indian Council of Medical Research (ICMR) found.
- ICMR guidelines currently leave it to medical practitioners to administer CP in case of moderately ill COVID-19 patients.
- The study’s authors said that the use of CP appeared to mitigate shortness of breath and fatigue among patients, and did correspond to a higher negative conversion of viral RNA, but ultimately did not improve outcomes over the period of evaluation.
Source: The Hindu
