You may have read/heard the news about plasma therapy for COVID-19.
In this article, let us quickly understand the ‘science behind plasma therapy’ in Layman’s language.
What is “Plasma”?
Is it a synonym to the blood we have in our bodies? Yes, you are partially correct. Plasma is a part of the blood like white blood cells, red blood cells, and platelets. It is the most substantial part of our blood and makes about 50-60 % of our blood. Plasma contains salts, water, and enzymes. These substances keep our bodies healthy.
Antibodies and antigen ?
Apart from substances like salts, water, and enzymes, the plasma contains a remarkable content called “antibodies” (yes, there are other more essential components also, but antibodies are crucial to understanding plasma therapy).
Antibodies protect us by fighting with antigens, such as bacteria, viruses responsible for diseases. So, if a foreign body (or antigen) attacks us, our immune system produces a specific antibody and kills the antigen to recover ourselves from that particular disease. Therefore, the antibodies are like the soldiers for our body,
Now, let’s say, a patient ‘A’ is recovered from a disease ‘D’ with the help of his / her antibodies developed in the plasma. Can we use these antibodies for other patients, who cannot fight disease ‘D’ with their immunity? Fortunately, the answer is ‘YES’!
Plasma therapy
By this time, you would have got the idea behind the ‘plasma therapy.’
In simpler words, “plasma therapy” is the transfusion of antibodies from the recovered patient’s plasma to the critically affected patient’s body (plasma). It is important to keep in mind that these antibodies are specific for the diseases.

Well, the plasma therapy is not a new concept to the World. During Spanish influenza (1918), it was used, but with the successful mixed results. In the 1920s, it was used to treat scarlet fever. A recent example is it’s use to fight the Ebola virus.
Plasma therapy in Covid-19
Recently, the US Food and Drug Administration has announced that it will allow the use of Covid-19 diseased plasma for treating the patients ( who are very serious). The rules to check the eligibility to donate blood is very stringent and can be found on US Food and Drug website . The donor must be recovered fully from Covid-19 and can only donate plasma after 28 days after recovery. USFDA has mentioned many technical specifications mentioned other than this.
These antibodies are collected from recovered patients’ blood. The collected blood is then tested for various other diseases such as HIV, hepatitis B, etc. (so that the other patient doesn’t get these diseases). Once the blood samples are okay, then antibodies are extracted from the blood plasma and injected to the critically affected patients.
Apart from the USA, many countries have been trying their best to recover critically ill patients suffering from Covid-19 with the help of this therapy. Such as in India. On the other hand, there are ongoing struggles with this approach in other countries. Of course, there are more scientific challenges involved.
But nevertheless, let us all hope the best for human-beings !
I hope, you have gained a good understanding of the ‘science behind plasma therapy to treat Covid-19.’