Coronavirus: What is convalescent plasma therapy? Things you should know

With over 2.4 million cases already and over 165,000 deaths to coronavirus infections globally, the world seems to have become very helpless in the face of the Covid-19 pandemic. Scientists are scrambling for vaccines, drugs and other ways that could be used as treatment against novel coronavirus. With no surety of a definite treatment in sight, doctors around the world are dusting off a century-old treatment for infections: Infusion of blood plasma teeming with immune molecules that might help survivors beat the infection. The top medical research body of India, the Indian Council of Medical Research (ICMR), on April 16 approved a clinical trial for plasma treatment of those seriously ill with Covid-19.

Here's all you need to know

What is convalescent plasma therapy?

Plasma therapy uses antibodies found in the blood of people who have recovered from an infection (or convalesced), to treat patients who are infected.

How does plasma therapy work against coronavirus?

In this therapy, blood is drawn from a person who has recovered from the disease and the serum is separated and screened for virus-neutralising antibodies.

When attacked by a pathogen, our immune systems produce antibodies and in this therapy these antibodies from recovered patients are used to treat other sick people.

According to Neha Gupta, Infectious Diseases Consultant at Fortis Memorial Research Institute in Gurgaon, based on the type of severity of Covid-19 infection, immunity develops.

Immunity develops early in asymptomatic or persons with mild symptoms, while it develops later in severe and critically-ill Covid-19 patients, she explained.

Why is convalescent serum used?

When an infection strikes, the body starts making proteins called antibodies specially designed to target that germ.

Those antibodies float in survivors' blood specifically plasma, the yellowish liquid part of blood for months, even years.

How long will the coronavirus survivors' antibodies persist against the virus?

Doctors don't know how long survivors' antibodies against Covid-19 will persist. Convalescent plasma is an experimental procedure for coronavirus patients.

What is the process of donating plasma?

The process for donating plasma is similar to donating blood and takes about an hour. Plasma donors are hooked up to a small device that removes plasma while simultaneously returning red blood cells to their bodies. Unlike regular blood donation in which donors have to wait for red blood cells to replenish between donations, plasma can be donated more frequently, as often as twice a week, it said.

Does plasma therapy actually work as a treatment against coronavirus?

There's no proof it will work. But countries like the US, China, and more recently India are using it as a stopgap measure. Convalescent plasma is an experimental procedure for Covid-19 patients.

When was it widely used?

The plasma therapy was most famously used during the 1918 Spanish flu pandemic. It was also used during the Ebola epidemic, which started in 2013 and in 2003 against SARS. Even now, there is no vaccine or cure for SARS. The plasma therapy is also used against measles, bacterial pneumonia and numerous other infections before modern medicine came along.

How are doctors using the convalescent plasma trial in the case of coronavirus?

Studies are being planned to test convalescent plasma against regular care in sick patients, and to prevent infections among people at high risk of exposure such as health care workers.

National Institutes of Health (US) researchers are measuring survivors' antibody levels to learn how strong the vaccines under development must be to protect. Other teams, including at Beijing's Tsinghua University, are hunting which antibodies are most potent, to copy in a lab and turn into drugs.

Which countries are using plasma therapy against coronavirus?

Along with the US, China and Spain, Turkey, South Korea, Italy, the United Kingdom, are some of the few countries that are also looking at plasma therapy to help deal with the coronavirus crisis that has gripped the world. Even India has joined the bandwagon and has begun trial for plasma therapy.

Convalescent plasma therapy in India against coronavirus

Kerala is the first state in the country to have been given the nod to try this out, as a task force was already in place. Soon, plasma enrichment technique will also be used to treat severely-ill Covid-19 patients on trial basis in a Delhi government hospital.