What is Plasma Therapy, how it works and can it be effective in the treatment of COVID-19?
For COVID-19, no exact cure has been discovered yet. According to the Food and Drug Administration (FDA), the Convalescent Plasma has been studied in several outbreaks of other respiratory infections like SARS-CoV-1 epidemic, the H1N1 influenza virus pandemic, and the MERS-CoV epidemic. As COVID-19 is similar to SARS-CoV, might be convalescent plasma therapy prove to be effective and safe. Further FDA stated that more clinical trials are required for the same to prove.
What is Convalescent Plasma Therapy (CPT)?
When pathogens attack our body, our immune system starts working and releases proteins to fight with an infection. These proteins are known as antibodies. If the infected person produces a sufficient amount of protein then he or she will be recovered by antibodies itself.
In plasma therapy, such immunity can be transferred from a healthy person to sick with the help of blood plasma. Here convalescent plasma is the liquid part of the blood from the recovered patients of COVID-19. We can say that in plasma therapy the blood of the recovered person as it is rich in antibodies is used to treat other sick people. The idea behind the therapy is that antibodies produced by the patients who have had survived the virus will boost the immune system of those who are critically ill or fighting with the COVID-19 According to the Infectious Diseases Consultant at Fortis Memorial Institute in Gurugram, Neha Gupta, immunity develops early in asymptomatic or person with mild symptoms. Or we can say in contrast that the immunity develops later in severe and critically-ill COVID-19 patients.
Do you know about Plasma?
The liquid part of the blood is plasma. It is made up of large water and proteins. It provides a medium for red blood cells, white blood cells and platelets to circulate through the body. It also consists of crucial components of immunity known as antibodies.
What are antibodies?
Antibodies are produced in the body is a type of proteins that defend from the infection caused due to pathogen an antigen. After this, some blood cells start functioning as memory cells so that they can identify and defeat the same enemy if and when it again invades by quickly producing the same antibodies.
When was the Convalescent Plasma Therapy first time used?
The concept dates back more than a century that is in 1890 when a German physiologist Emil von Behring discovered that when he took the serum from an infected rabbit with diphtheria, it was effective in preventing the infection caused due to diphtheria. In the past, same types of treatments are used during several outbreaks, including Spanish flu pandemic 1918, the diphtheria outbreak 1920, etc. That time convalescent therapy was less effective and had substantial side effects.
The therapy was recently tried for Ebola virus and other coronavirus diseases like SARS in 2003 and MERS in 2012. The method was used with improved extraction and screening techniques and appears to be more safe and effective than ever before.
How does Convalescent Therapy work?
In this technique, the blood is ejected from the recovered patient from COVID-19. Then the serum is separated and screened for virus-neutralising antibodies. The antibodies rich serum is then administered to a COVID-19 patient showing severe symptoms.
According to Houston Methodologist, the process takes around one hour for donating plasma just like to donating blood. It is said that the donors of the Plasma are hooked up to a small device that removes plasma while simultaneously returning red blood cells to their bodies. In regular blood donation, donors have to wait for red blood cells to replenish between donations but in the case of plasma, it can be donated frequently, that is twice a week.
The plasma rich with antibodies is taken from the recovered patients of COVID-19 and then is infused into the bloodstream of other infected coronavirus patients. When the body gets into contact with external pathogens like bacteria or germs, it automatically starts a defence mechanism and started releasing antibodies.
According to the researchers, the therapy is not as simple as to obtain a significant amount of plasma from survivors is difficult. In the case of COVID-19, a new disease, where most patients are aged and already suffering from other diseases like hypertension, diabetes, etc. Therefore, effectiveness remains questionable.
Various trials and study related to Convalescent Plasma Therapy
In China, a study found the therapy as effective, on small sample size, in treating COVID-19 patients. In the study, it was given that a trial was conducted in which 200 ml dose of convalescent plasma was administered to 10 adult COVID-19 patients with severe symptoms. The patients showed significant improvement and in seven patients virus disappeared without any severe adverse side effects. In this therapy, the sick acquires only temporary passive immunisation. It last mainly less than a week that is till the time the injected antibodies remain in the bloodstream.
In Houston also, the same trial was conducted and it is said that three critical ill COVID-19 patients are also showing signs of recovery from the convalescent plasma therapy.
According to the US Food and Drug Administration (FDA), prior experience with respiratory viruses and the data that have emerged from China shows that the therapy has the potential to lessen the severity or shorten the length of illness caused by COVID-19.
In India, the Indian Council of Medical Research (ICMR) has given the nod to Kerala to conduct convalescent plasma therapy. Kerala is the first state in the country. ICMR has not yet recommended it as a treatment option outside of clinical trials.
Several countries including China, South Korea, US and UK have also tried this therapy treatment. Some leading medical journals say that initial small trials are encouraging. Trials and researches are going for COVID-19 treatment. Therefore, it is necessary to take precautions as per the advisory of the government. Stay home and be safe!