Coronavirus – Disease, Medical Sciences Involved & Preventive Measures

Convalescent Plasma Therapy

Note4Students

From UPSC perspective, the following things are important :

Prelims level : Convalescent Plasma Therapy

Mains level : Coronovirus outbreak and its mitigation

With no specific treatment available for novel coronavirus disease and a vaccine at least a year away, the US Food and Drug Administration (FDA) has approved use of blood plasma from recovered patients to treat severely critical COVID-19 patients.

Convalescent Plasma Therapy

  • The therapy seeks to make use of the antibodies developed in the recovered patient against the coronavirus.
  • The whole blood or plasma from such people is taken, and the plasma is then injected in critically ill patients so that the antibodies are transferred and boost their fight against the virus.
  • A COVID-19 patient usually develops primary immunity against the virus in 10-14 days.
  • Therefore, if the plasma is injected at an early stage, it can possibly help fight the virus and prevent severe illness.

How often has it been used in the past?

  • This therapy is no new wonder. It has been used several times.
  • The US used plasma of recovered patients to treat patients of Spanish flu (1918-1920).
  • In 2014, the WHO released guidelines to treat Ebola patients with convalescent whole blood and plasma.
  • In 2015, plasma was used for treating MERS patients.

How is it done?

  • 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.

WHO’s guidelines

  • WHO guidelines in 2014 mandate 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, the WHO guidelines state.

How optimistic is the latest move?

  • COVID-19 does not have a specific treatment, only supportive care— including antiviral drugs, oxygen supply in mild cases and extracorporeal membrane oxygenation.
  • Plasma can be infused into two kinds of COVID-19 patients— those with a severe illness, or individuals at a higher risk of getting the virus.
  • However, that while plasma transfers immunity from one person to another, it is not known if it can save lives in COVID-19 infection.
  • The treatment could be effective for patients in the age group 40-60, but may be less effective for people aged beyond 60 years.

Can it be done in India?

  • India has facilities for removing 500 ml of plasma from a donor using aphaeresis.
  • For this experimental therapy to be tried out, the Drug Controller General of India will first have to grant blood banks approval for removal of plasma from recovered COVID-19 patients.
  • The procedure is simple and can be done in India, but it is important to control the risk of infection during transfusion, and the patient’s acceptance is required.
  • It’s like a vaccine. It will engulf the virus and kill it. But it is easier said than done. We may need a series of approvals which India has never done before.
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