In the absence of standard treatment or vaccine for the novel coronavirus, which has killed over 19 lakh people globally, more and more countries are looking at 'convalescent-plasma therapy' as a possible way to treat the viral infection.
India has joined the list of countries using plasma therapy earlier this month. The US health regulator Food and Drug Administration (FDA) has also given go-ahead to the Columbia University to launch clinical trials to determine whether blood plasma from COVID-19 survivors can be used to prevent infections in high-risk individuals. The UK too has started clinical trials.
In India, Kerala, Karnataka, Delhi, Gujarat and Maharashtra, among others, have started clinical trials for the plasma-based treatment.
How does plasma therapy work in COVID-19 patients?
When a pathogen like novel COVID-19 infects the body, the immune system produces antibodies to fight the invading virus. In a recovered person, the antibody can be found in the plasma, the liquid that holds blood cells. The plasma constitutes around 55% of blood in the human body.
In the plasma therapy, antibody is taken from a recovered patient and put into a sick person's body. The antibody then creates passive immunization in the sick person to combat the virus and recover. Passive immunisation is a technique to achieve immediate short-term immunisation against infectious agents by administering pathogen-specific antibodies.
What is the procedure?
The plasma with antibody is harvested from the blood drawn from a recovered person and the blood is returned to the donor's body. Then, only the extracted plasma is administered to the sick patient.
As there are no approved treatments for COVID-19, critical patients are presently helped with supplemental oxygen and mechanical ventilation. Besides, there is also case-to-case basis treatment administered to patients depending on their comorbidity conditions such as diabetes. In this scenario, researchers are seeing positive signs that plasma therapy could emerge as a possible treatment for the deadly virus.
How is it being used in India?
The ICMR has recently permitted states to carry out this "experimental" procedure through clinical trials on severe category patients infected by COVID-19. It has not yet recommended plasma therapy as a standard treatment for COVID-19.
The Delhi government on April 24 announced that it will aggressively push for plasma therapy saying that it was showing "positive results". After conducting increased clinical trials the government will seek the Centre's nod to use the therapy on all serious COVID-19 patients across Delhi.
The move comes following improvement in the condition of a 49-year-old-male who was administered plasma therapy at Max Hospital, Saket. The patient has been taken off ventilator support, according to the hospital.
Has it been used before?
Earlier in 2014, the use of convalescent plasma, collected from patients who had recovered from Ebola virus disease, was recommended by the World Health Organisation (WHO) as an empirical treatment during the outbreak. During the H1N1 virus outbreak of 2009 and SARS epidemic of 2003, plasma therapy was used to treat patients.
