Until a drug or vaccination emerges for Corona, any medical system is left with the choice of trying several potentially useful methods of treatment. One among such measures that India is looking to adopt is convalescent-plasma therapy. But it can’t be done by each and everyone involved in the treatment of Covid-19 patients. Indian Council of Medical Research (ICMR) permits some institutes who have been approved by the Drugs Controller General of India, who fulfil the criteria like prior experience in conducting clinical studies and presence of necessary expertise, equipment and infrastructure for the study.
On April 21, the Karnataka Chief Minister tweeted that they have obtained permission for plasma therapy. On April 18, The Indian Express reported that a Gujarat government hospital got the nod for clinical trial of Plasma therapy. On April 21, Live Mint reported that a 49-year old COVID-19 patient showed improvement after plasma therapy and weaned off ventilator support.
Let’s try to explore the nitty-gritty of plasma therapy to COVID-19 patients.
What is Plasma Therapy?
When a pathogen like novel coronavirus infects, our immune systems produce antibodies. The antibodies span out to identify and mark the invading virus. White blood cells attach the identified intruders, and the body gets rid of the infection. The therapy, like blood transfusion, harvests the antibody from a recovered patient and is then administered to a sick person. Helped by the antibody, the immune system mounts a robust combat on the virus.
How It Is Done?
Blood is drawn from a person who has recovered from COVID-19 sickness. The serum is separated and screened for virus-neutralizing antibodies. Convalescent serum, that is the blood serum obtained from one who has recovered from an infectious disease and especially rich in antibodies for that pathogen, is then administered to a COVID-19 patient. The sick acquires passive immunisation.
Is there a formal process to get treated by this method?
Plasma therapy for COVID-19 is being treated as clinical trial. It will be carried only after getting an informed consent and will be explored only in the case of severely affected.
Is this a kind of vaccination?
No. Vaccination provides lifelong immunity. In the case of passive antibody therapy, the effect lasts only up to the time the antibodies injected remain the bloodstream.
Are There any recent examples of plasma therapy?
Whenever a new viral outbreak takes places, there are no drugs to treat it. Convalescent serum has been used during viral epidemics in the past. During the outbreak of 2009–2010 H1N1 influenza virus pandemic, patients with an infection requiring intensive care were administered convalescent serum and improvement was recorded in many cases. The viral burden reduced, and the death rate could be lowered. The procedure was also useful during the Ebola outbreak in 2018 across Africa.
The risks and the challenges
In the modern-day blood banks, sophisticated screening is possible which reduce the risk at receiver’s end. The donors will undergo tests for hepatitis, HIV, malaria, and so on to ensure that they do not pass on a different pathogen to the receiver.
However, the challenge lies in the difficulty of obtaining significant amounts of plasma from survivors. Most of the COVID-19 victims are aged and have pre-existing medical conditions. So, not all recovered patients can volunteer to donate blood.