Study: Blood plasma given early reduces risk for hospitalization from COVID-19

Study: Blood plasma given early reduces risk for hospitalization from COVID-19
Blood transfused from people who have recovered from COVID-19 to those newly infected reduces the latter's risk for hospitalization due to the virus, according to a new study. File photo by Bill Greenblatt/UPI | License Photo

Dec. 21 (UPI) -- Blood plasma collected from people who have recovered from COVID-19 reduces the risk for hospitalization among those infected with the virus, a study posted online Tuesday found.

The approach, which involves transfusing so-called "convalescent" plasma from people who have recovered from COVID-19, works best when it is administered early, within seven days of diagnosis, the researchers said.


Patients given plasma with high levels of antibodies against the virus had a 54% lower risk for hospitalization compared with those given placebo plasma, or blood without COVID-19 antibodies, the data showed.

Antibodies are proteins produced by the immune system to fight off viruses.

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"We have known for more than a century that antibodies are most effective when they are given early in the course of [an infectious] disease," study co-author Dr. Arturo Casadevall said on a call with reporters Tuesday.


The treatment "can be used to reduce hospitalizations, which is very good as we are in the middle of the Omicron surge," said Casadevall, chair of molecular microbiology and immunology at Johns Hopkins Bloomberg School of Public Health in Baltimore.

The Omicron variant of COVID-19 was first identified in South Africa in late November, but the potentially highly transmissible strain is already the common one in circulation in the United States, according to the Centers for Disease Control and Prevention.

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The study is a pre-print that has not yet been published in a medical journal, meaning it has not yet been peer-reviewed, Casadevall and his colleagues acknowledged on the call.

However, "the data is the data and it will not change after peer review," he said.

Convalescent plasma, which is collected from people who have recovered from an illness, has been used to treat infectious diseases for more than a century, the Mayo Clinic says.

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People who have survived a serious infection have built up antibodies against the virus that caused their illness, and these antibodies remain in their bloodstream, the Johns Hopkins researchers said on the call.

Once they have been transfused from recovered patients into those who are newly infected or ill, these antibodies can provide the immune system with a needed boost to fight off the virus, they said.


In August last year, the Food and Drug Administration authorized the use of convalescent plasma to treat patients hospitalized with COVID-19.

The National Institutes of Health has also included the treatment in its guidelines for the management of the virus, provided the collected plasma contains high levels of antibodies against it.

Earlier research has found that the approach is effective at resolving severe illness in some infected patient, although the NIH stopped a study of it earlier this year, citing a lack of clinical benefit.

However, based on its findings, the Johns Hopkins researchers would like to see the agency greenlight the approach on an outpatient basis, meaning infected patients can receive the therapy without being admitted to the hospital, they said.

They plan to meet with the FDA to discuss their findings, they said.

For this study, they collected plasma with high levels of antibodies against the original variant of the virus, first discovered in Wuhan, China, in 2020, before COVID-19 vaccines were available.

Donors had to meet the same criteria for community blood donation and had to have recovered from COVID-19 with high levels of antibodies against the virus in their blood, according to co-author Dr. Evan Bloch, associate director of transfusion medicine at Johns Hopkins University.


The researchers then administered the treatment, via transfusion within seven days of virus diagnosis, to 1,181 adults at 27 sites nationally, including two on Native American reservations, and 81% of the participants were unvaccinated at the time of the study, they said.

All of the plasma recipients had had symptoms for eight days or less at the time of their treatment, most of the participants were in their mid-40s and 57% were women, the researchers said.

Native Americans as well as Black and Hispanic Americans, who each represented 12% of the study population, are at higher risk for severe illness from COVID-19 than White Americans, according to the Centers for Disease Control and Prevention.

Transfusions were administered on an outpatient basis, meaning none of the participants were admitted to the hospital at the time they received the treatment, the researchers said.

About 3%, or 17, of the 592 participants who received convalescent plasma were admitted to the hospital due to the virus, compared with just over 6% or 37, of the 589 in the placebo group, the data showed.

Fifty-three of the 54 people hospitalized in both groups were unvaccinated, according to the researchers.

About 6% of the participants who received convalescent plasma experienced side effects such as transfusion reactions, including redness around the injection site, compared with 9% of those who received the placebo, the researchers said.


Although plasma from people who recovered from the virus would need to be stockpiled, this process could be "scaled up quickly," given that most hospitals already have the infrastructure in place for collection, said study co-author Dr. Kelly Gebo, who was also on the call.

Hospitals already collect, store and administer plasma for other purposes, and its use is highly regulated to ensure patient safety, said Gebo, a professor of medicine at Johns Hopkins.

Early findings suggest that the Omicron variant may not respond well to treatment with currently available monoclonal, or laboratory-created, antibodies, she said.

However, convalescent plasma is a more "durable" therapy than monoclonal antibodies, in that it can be collected from recovered patients as new variants emerge, meaning they would have immune proteins capable of fighting off the strains, according to Bloch, who was also on the call.

Convalescent plasma "provides the same antibodies as [the COVID-19] vaccines instantly," study co-author Dr. David Sullivan said on the call.

"Expanding outpatient access would provide an immediate single-dose therapy that is desperately needed," said Sullivan, a professor at the Johns Hopkins Bloomberg School of Public Health.

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