Understanding Convalescent Plasma 

April 13, 2021

What is Convalescent Plasma
A person who has recovered from Covid-19 has antibodies to the virus that causes it. These antibodies are present in Plasma, which is a component of blood. Many clinicians believe that this Plasma which contains antibodies will boost the immune system and help a patient with Covid-19 in fighting the virus. This Plasma, which is collected from a person who has recovered from Covid-19 is termed as Convalescent Plasma or Recovered Plasma.

Clinical trials on efficacy
The efficacy of Convalescent Plasma is a matter of debate. The Indian Council of Medical Research (ICMR), which is under the Ministry of Health and Family Welfare, Govt. of India, had conducted multi-centric, randomised trials to study the efficacy of Convalescent Plasma. They have come to the conclusion that Convalescent Plasma does not offer any significant benefit to the patient. There are trials done in other countries that have come to the same conclusion. Some other trials suggest that Convalescent Plasma may reduce the severity of the disease, particularly if given at a very early stage after infection.

Off Label Use
Clinicians, however, continue to prescribe Convalescent Plasma. In response to this demand, and in acceptance of the fact that there is no exact treatment for Covid-19, the Drugs Controller General of India (DCGI) has approved the “off label” use of Convalescent Plasma. This means that the authorities are not sure about the efficacy of the therapy. The therapy can therefore be given only on the prescription of the treating doctor, and with the consent of the patient/family.

Collection process
Collection of any specific component of blood is done by a process called “apheresis”. In this process, the blood bag in which the donor donates blood is connected to a cell-separator machine during the process of donation. After drawing @ 350 ml of blood as in routine blood donation, the cell separator collects the Plasma in an adjoining bag, and sends back the remaining components to the door’s vein. This cycle is repeated one more time in the case of Plasma donation. Being a large component of “Whole” Blood, a sizeable quantity of Plasma is collected in each cycle. Between 400-450 ml is collected after 2 cycles, and this is converted in 2 units each of 200-225 ml.

Storage and Shelf-life
Convalescent Plasma should be frozen within 8 hours and stored in a Deep Freezer with temperature of -18° C or lower. It has an expiry date of 1 year from the date of collection.

Donor eligibility criteria
Convalescent Plasma, very obviously, has to be collected from a person who has recovered from Covid-19. The following rules apply in our country :

1. Donor should have an RT-PCR report which shows the presence of the virus.
2. At least 28 days should have elapsed after full recovery from the virus.

After the donor visits the Blood Centre:

1. Donor will be counselled about the procedure.
2. Donor will be interviewed by a medical person to check if all routine blood donor criteria are met. This will include tests for haemoglobin, blood pressure, temperature and pulse.
3. Blood sample will be taken to check if the donor has the required level of antibodies. It will also be checked for blood-transmissible infections.
4. Donor’s veins will be checked for suitability for apheresis

The donor will be taken up for the process of “apheresis” after fulfilling all the above criteria. As mentioned earlier the process of apheresis for collection of Convalescent Plasma will be completed in 20-25 minutes

Collection Centres
Blood Centres who wish to participate in the collection of Convalescent Plasma must obtain specific approval from the Drugs Controller’s office. Today, there are a number of blood centres, both hospital-based as well as stand-alone, who have been given permission to collect Convalescent Plasma.

Click to view the PDF of Blood Centres (Hospital-based and Stand-alone) which collect Convalescent Plasma in and around Mumbai 

The ground reality
Many clinicians who are treating Covid-19 patients believe that Convalescent Plasma therapy is useful. There is a huge demand for Convalescent Plasma. It is therefore necessary that the blood transfusion service makes Convalescent Plasma available to those seeking this option. The onus of finding donors/Convalescent Plasma should not be placed on the patient/family.

Patient’s dilemma
Doctors and hospitals who prescribe Convalescent Plasma, have put the responsibility of obtaining it, on the patient’s family and friends. They are provided with a Prescription Letter from the Hospital/Doctor with the instruction to procure Convalescent Plasma as a life-saving measure. The desperate search, without a clue on the direction to be taken, begins. The family starts looking for Blood Centres which have stock of Convalescent Plasma or will look for donors who fulfil the eligibility criteria for donation of Convalescent Plasma.

After location of Convalescent Plasma
The patient’s relatives are required to take the Prescription letter from their doctor, and blood sample of the patient for checking for compatibility with the available Convalescent Plasma unit. The Blood centres may have their own formats which are to be filled by the treating doctor and the patient.

Patient’s family may also note that the Maharashtra Health Ministry has capped the price of Convalescent Plasma at Rs. 5500/- for one unit (200-250 ml) of Convalescent Plasma.

Action required on the ground
The Blood Transfusion Authorities should take the responsibility of adequacy and safety of blood and its components including Convalescent Plasma. This will ensure that there is no panic, and will pave the way for collection of Convalescent Plasma from voluntary, non-remunerated donors. The following steps ought to be taken:

• A) All Covid-19 hospitals and quarantine centres should be directed to include a counselling session for patients at the time of their discharge. This session, apart from briefing them about steps to be taken after discharge, should also inform them about the possibility of lives being saved by their act of plasma donation. Their consent should be taken for sharing their contact details with an authority like the State Blood Transfusion Council. This directive should go to both public and private hospitals. The State Blood Transfusion Council should appoint counsellors who will motivate recovered persons to come forward for plasma donation. This same effort of motivating recovered persons to come forward should also be done through the media. On obtaining their approval, the SBTC should choose the nearest approved Plasma Collection Blood Centre, and inform the donor of the same. If 10 counsellors call 20 persons a day and have a success of just 10 %, we would have 20 donations every day, which would translate to 40 units of recovered Plasma per day. SBTC should maintain a record of the inventory of Convalescent Plasma, and direct the Collection Centres on the priorities for supply 
• By divorcing the patient from the donor, we would be facilitating the implementation of the principles of National Blood policy of collecting blood and its components only from voluntary, non-remunerated, regular donors. This would also ensure adequacy of Convalescent Plasma units and a clear direction to patient’s families.

• B) Permission should be granted for collection of Convalescent Plasma from Whole Blood donation. According to guidelines of the National Blood Transfusion Council, a person who has recovered from Covid-19 can donate blood if it is more than 28 days from the date of recovery. Any efficient Blood Centre, in the normal course, makes components from blood that is collected. Around 200 ml of Plasma is obtained in this manner. This Plasma can be termed as Convalescent Plasma if it contains the required level of Antibodies. This will significantly bring down the costs, enable donations from those whose veins are not suitable for apheresis, motivate those who have apprehensions about apheresis, and facilitate donation of Convalescent Plasma in areas which do not have the facility of apheresis.

This information has been provided by

Mr. Vinay Shetty

Vice President

Think Foundation

Tags: Health & Covid

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