Context: India is all set to try out a Convalescent Plasma Therapy that involves attempting to boost immunity of a serious patient by utilising the concept of passive immunity.
Status of using plasma therapy in India
- Steps taken by Indian Council of Medical Research (ICMR)
- It is currently framing a protocol for infusing blood plasma from people who have recovered from COVID-19 into serious patients.
- This will only be applied by way of a clinical trial, in patients who are in a severe condition, or on ventilator.
- ICMR is currently in the final stages of making a protocol for convalescent plasma therapy and after that the approval from the drug controller general of India will be awaited.
- Experiments in Kerala
- State has gone a step ahead and won Indian Council of Medical Research’s (ICMR) approval for the clinical protocol exploring the feasibility of an experimental therapy.
- Later on the state would also need clearance from the national drug controller before going ahead with such a trial.
Status of plasma therapy worldwide
- U.S: COVID-19 convalescent plasma has not yet been approved for use by FDA, it is regulated as an investigational product.
- Earlier uses of the therapy:
- It has been tried for several diseases such as H1N1, SARS and Ebola.Most recently it was used for Ebola.
- The WHO had issued a detailed guidance document for its use in the wake of the Ebola outbreak, to be used as an “empirical treatment modality”.
About Convalescent Plasma Therapy
Image source: The Hindu
Procedure of Therapy:
- The process to infuse plasma in a patient can be completed quickly. It only requires standard blood collection practices, and extraction of plasma.
- If whole blood is donated (350-450 ml), a blood fractionation process is used to separate the plasma.
- Otherwise, a special machine called aphaeresis machine can be used to extract the plasma directly from the donor.
- While blood is indeed extracted from the donor, the aphaeresis machine separates and extracts the plasma using a plasma kit, and the remaining blood components are returned into the donor’s body.
Significance of the plasma therapy during COVID-19:
- At present there are no specific antiviral agents which have been found to be effective in the treatment of COVID-19.
- Convalescent plasma therapy is not new and has been used by doctors to treat critically ill patients earlier.
- Strengthening preparedness for next wave: Though, except for a few, most COVID-19 patients in Kerala have not even required ventilatory support, the clinical protocol for administering plasma therapy will strengthen preparedness to treat severe COVID-19 patients during the second or third wave.
WHO Guidelines on Plasma Therapy, 2014:
- It mandates a donor’s permission before extracting plasma.
- Plasma from only recovered patients must be taken, and donation must be done from people not infected with HIV, hepatitis, syphilis, or any infectious disease.
- If whole blood is collected, the plasma is separated by sedimentation or centrifugation, then injected in the patient.
- If plasma needs to be collected again from the same person, it must be done after 12 weeks of the first donation for males and 16 weeks for females.
Understanding some basic concepts
Active Immunity vs Passive Immunity
Source:US dept. of health
Developing passive immunity
- Temporary immunity can be achieved in a person without injecting any antigen.
- This is done by infusing antibodies, activated T cells or both obtained from the blood of someone else or from some other animal that has been actively immunised against these antigens.
- These antibodies last for two-three weeks and during that time, the person is protected against the invading disease.
- Activated T cells last for a few weeks if transfused from another person and for a few hours to a few days if transfused from an animal.
- Such transfusion of antibodies or lymphocytes to confer immunity is called passive immunity.
- Plasma is the matrix on which the blood cells float.
- It also houses crucial components of immunity known as antibodies.
- Composed of 90% water, salts, lipids and hormones, it is especially rich in proteins (including its main protein albumin), immunoglobulins, clotting factors and fibrinogen.
- Functions of the plasma:Transporting blood cells and nutrients; regulating the body’s water and mineral salts; irrigating tissues; providing a defence against infections; and coagulating blood.
- Red blood cells, white blood cells and platelets are suspended in plasma.
About Antibodies and their working:
- Antibodies are the immediate warriors who fight an invading pathogen called antigen to defeat it.
- Once that is done, some blood cells function as memory cells so that they can identify and defeat the same enemy if and when it invades again by quickly producing the same antibodies.
Elements of blood
Drugs Controller General of India (DCGI)
- It is a department of the Central Drugs Standard Control Organization of the Government of India.
- It is responsible for approval of licences of specified categories of drugs such as blood and blood products, IV fluids, vaccines, and sera in India.
- Drug Controller General of India, comes under the Ministry of Health & Family Welfare.
- DCGI sets standards for manufacturing, sales, import, and distribution of drugs in India.
The Central Drugs Standard Control Organisation(CDSCO)
- CDSCO under Directorate General of Health Services, Ministry of Health & Family Welfare, Government of India is the National Regulatory Authority (NRA) of India.
- Under the Drugs and Cosmetics Act, 1940, CDSCO is responsible for
- approval of Drugs,
- conduct of Clinical Trials,
- laying down the standards for Drugs,
- control over the quality of imported Drugs in the country and
- coordination of the activities of State Drug Control Organizations by providing expert advice with a view to bring about the uniformity in the enforcement of the Drugs and Cosmetics Act.