Convalescent Plasma Therapy: What is it and how blood plasma works to treat COVID-19 patients?
Convalescent Plasma Therapy, also known as passive antibody therapy, provides a person with already developed antibodies to fight a virus.
Convalescent Plasma Therapy: In order to combat the COVID-19 pandemic, researchers and scientists are working tirelessly to develop a proper treatment for patients infected with the novel Coronavirus. Amid testing the already existing antiviral drugs and new ones, the researchers have come across the Convalescent Plasma Therapy, which could be a potential treatment for the virus.
Several countries including China and the US have already started the clinical trials of the Convalescent Plasma Therapy due to the absence of a coronavirus-specific treatment to cure the infected patients.
The Convalescent plasma therapy was first used during the 1918 Spanish Influenza outbreak. The approach was used recently during the outbreak of SARS, MERS and Ebola viruses.
What is Convalescent plasma therapy and how does it work to fight COVID-19?
- Convalescent Plasma Therapy, also known as passive antibody therapy, provides a person with already developed antibodies to fight a virus.
- Under the Plasma Therapy, the COVID-19 patients will be infused with an antibody-rich blood plasma of the people who have recovered from the novel Coronavirus.
- The Convalescent Plasma Therapy is based on the antibodies and proteins developed by the immune system that protects the body from any potential harm.
- When any virus attacks the body, the immune system produces antibodies to attack the virus. These antibodies are produced by immune cells 'B lymphocytes', found in blood plasma.
- The person who recovers from a virus has developed antibodies that stay in blood to fight the same virus, if it returns. And if these antibodies are infused into other person infected with the same virus, they recognise the virus and attack it. However, these antibodies stay for short period in other person's blood.
- Some antibodies neutralize the virus and some work by mobilizing the immune cells to combat a disease.
Is the Convalescent Plasma Therapy a success in treating COVID-19 patients?
It is not yet clear that which mechanism will be followed by COVID-19 antibodies to fight off the disease. However, it is expected that the infusion of blood plasma will boost the passive immunity until the patient develops his or her own targeted ability to combat the virus.
Results of Convalescent plasma therapy trials conducted in China: As per the tests conducted on a few patients of Coronavirus in China, the therapy came out as a promising option for severe cases. The tests were conducted in 10 patients who were given a single dose of blood plasma of recovered patients.
The results showed that the coronavirus disappeared from patients’ blood in 7 days; lung lesions improved within 7 days and clinical symptoms improved significantly within 3 days.
How many patients can be treated with one donor's plasma?
The blood plasma of a donor can produce two doses and a person needs only one dose to get enough antibodies.
Drawbacks of Convalescent Plasma Therapy
- Therapy is expensive
- Limited number of plasma donors
Trials of Convalescent Plasma Therapy in India
ICMR approved Convalescent Plasma Therapy for COVID-19 patients in India
The Indian Council of Medical Research (ICMR) has finalised the research protocols for the plasma therapy and has approved the use of therapy for COVID-19 patients in India. ICMR needs the approval of the Drugs Controller General of India (DCGI) before the conducting the clinical trials. The DCGI approval is needed for collecting the blood donation for this kind of treatment.
Who all will get Convalescent Plasma Therapy treatment in India?
Only the critically-ill patients who need support care will get Plasma Therapy treatment. The therapy will not be used for patients showing mild or no symptoms .
Kerala to be the first state to commence Convalescent Plasma Therapy
With the ICMR giving it approval to Kerala for conducting the trials of plasma therapy, the Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) will soon begin with the trials by April end.
PGIMER Chandigarh to soon launch trials for Plasma Therapy
Dr Jagat Ram, Director of the Post Graduate Institute of Medical Education and Research (PGIMER) Chandigarh, recently announced that the institute will soon begin with the trials of Convalescent plasma therapy in collaboration with another Covid-19 centre.
Trials of plasma therapy in the US
Convalescent plasma therapy gained momentum in the United States on March 28, 2020 when the two US hospitals, namely Houston Methodist Hospital and Mount Sinai Medical Center, became the first to use it on COVID-19 patients. However, the results are still awaiting.
The Food and Drug Administration (FDA) of the US had approved the use of therapy in clinical trials for treating severe cases of COVID-19.