Contributed by – Healthians team
As the world is rushing towards finding the cure for coronavirus, some researchers believe convalescent-plasma therapy could be a possible way to treat coronavirus patients, until we have the vaccine. Some Indian states have already started plasma therapy while some are either waiting for approval from the Indian Council of Medical Research (ICMR) or have got the approval but have not started the therapy yet. Meanwhile, in the US, 6000 coronavirus-recovered patients have donated their plasma.
But the question remains – Can convalescent-plasma therapy treat COVID-19 patients? For that answer, let us first understand what this therapy is.
What exactly is convalescent-plasma therapy and how does it work?
Plasma is the liquid part of the blood and makes up around 55% of it, with red blood cells, white blood cells and platelets making up the remaining 45%. Plasma is 91-92% water and is light yellow in color.
When your body is exposed to a foreign pathogen, your body produces antibodies which can fight off those pathogens to keep you safe. These antibodies, which are your personal army against foreign invaders, are found in plasma. So, once you recover from an illness, these antibodies stick around for a while in your plasma to fight the virus, if it comes back. Also, each kind of virus has its own antibodies.
So, what doctors are doing here is: they are extracting the plasma from a recovered patient of coronavirus and then transfusing them into a severely ill COVID-19 patient with a hope that the antibodies of the recovered patient may accelerate the war against the disease by kick-starting the immune system of the ill patient. Since immunity against the virus is “borrowed” here, it is called passive immunity.
Has plasma therapy worked before?
Whenever in history we have seen a new disease, convalescent plasma therapy was used to treat the patients. It was used when the Spanish Flu took over the world in 1918. It was again used during the SARS epidemic in 2003, the H1N1 virus outbreak in 2009 and during the Ebola outbreak in 2014. Plasma therapy has also proved effective in the treatment of rabies, hepatitis B, polio, measles and influenza. But with the invention of antibiotics, the use of plasma therapy rapidly declined.
What do researchers have to say about using plasma therapy to treat COVID-19 patients?
The medical community is still trying to determine whether convalescent plasma will help those battling COVID-19. It is still too soon to make any claims. Some patients recovered soon after getting the therapy while some showed no signs of improvement. Hence, nothing can be said definitively yet.
However, the ICMR has allowed some states to use plasma therapy as an “experimental” procedure through clinical trials on severely ill COVID-19 patients. It is still not recommended as a standard treatment for COVID-19.
Who can donate their plasma?
The donation process is quite similar to that of blood donation. The phlebotomist will insert a needle into an arm vein to draw the blood. But instead of the blood being pumped into a bag, it will go directly into a machine which will separate the plasma from the blood. And the blood drawn will be returned to the donor’s body.
To qualify for plasma donations, a donor must:
- Pass normal blood-donation requirements.
- Must have had a positive diagnosis of COVID-19 in the past.
- Be COVID-19 symptom-free for at least 14 days and negative COVID-19 test.
Are there any risks involved in plasma therapy?
Likely risks of plasma therapy could be:
- Risk of non-COVID-19 infection through contamination or improper screening of plasma.
- Risks associated with blood transfusion.
- Worsening of immune-mediated damage.
No definitive studies exist showing the effectiveness of plasma therapy to treat coronavirus disease. It will be the first time that the medical and scientific communities will conduct this type of rigorous study to determine the effectiveness of plasma therapy.
