Convalescent plasma did not stop COVID-19 progression in high-risk patients, shows NIH trial

COVID-19 convalescent plasma, also known as “survivor’s plasma,” is blood plasma derived from patients who have recovered from COVID-19.

Moneycontrol News

August 19, 2021 / 05:18 PM IST

COVID-19 representative image.

Convalescent plasma did not prevent disease progression in high-risk group of COVID-19 outpatients when administered within the first week of their symptoms, revealed the final results of a clinical trial funded by National Institutes of Health (NIH), US Department of Health and Human Services.

COVID-19 convalescent plasma, also known as “survivor’s plasma,” is blood plasma derived from patients who have recovered from COVID-19.

Principal investigator Clifton Callaway said that the reduction they observed was less than two percent.

“We were hoping that the use of COVID-19 convalescent plasma would achieve at least a 10% reduction in disease progression in this group, but instead the reduction we observed was less than 2 percent,” said Clifton Callaway, M.D., Ph.D., the contact principal investigator for the C3PO trial and professor of emergency medicine at the University of Pittsburgh. “That was surprising to us. As physicians, we wanted this to make a big difference in reducing severe illness and it did not.”

The trial was stopped in February as it did not prevent the progression of the infection as expected, a statement from NIH said.

COVID-19 Vaccine

Frequently Asked Questions

How does a vaccine work?

A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.

How many types of vaccines are there?

There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.

What does it take to develop a vaccine of this kind?

Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.

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