Convalescent Blood Plasma Not as Effective Against COVID-19 as Once Thought

For months, patients suffering from serious illness because of COVID-19 have had some measure of hope. With scant treatments available, some providers have been using convalescent blood plasma from people who have recovered from COVID-19 to treat those still suffering from the disease.

The treatment should work, in theory. Convalescent blood plasma from those who have recovered from the virus is typically full of antibodies that can help ward off serious complications of COVID-19. Injecting seriously ill patients with blood plasma should help their immune system fight off the disease, but scientists are waking up to the fact this treatment may not be all it’s cracked up to be.

Putting Faith in Blood Plasma

Doctors still don’t have a lot of options when it comes to treating COVID-19. In the early days of the pandemic, Dr. Nicole Bouvier of the Icahn School of Medicine at Mount Sinai Hospital in New York decided to use this experimental technique as a last resort.

She was the first doctor to get approval from the FDA to use convalescent blood plasma on an emergency basis.

For Dr. Bouvier, the idea made perfect sense. “We have this new disease that didn’t have any known therapies, and convalescent plasma has been used in new epidemic and pandemic diseases,” she recalls thinking at the time, adding that it was used during an outbreak of Ebola in West Africa a few years ago.

As the virus continued to ravage New York, Dr. Bouvier and her team suddenly found themselves facing a massive undertaking. They had to convince COVID-19 survivors to donate their blood in the middle of a pandemic. Of the original 70,000 volunteers, they were able to identify 20,000 people with enough antibodies in their systems for use.

Dr. Bouvier says they treated over 1,400 patients with convalescent blood plasma last spring, but she never really knew whether it was working.

After months of collecting and analyzing data, she decided it was finally time to call it quits and cut off access to the experimental treatment.

What Went Wrong?

With so few options on the table, Dr. Bouvier says it wasn’t an easy decision to make, but the treatment ultimately wasn’t doing her patients much good.

“The straw that broke the camel’s back was two very large cohort trials,” she says, including the RECOVERY Trial in the U.K., which studied the efficacy in more than 10,000 volunteers, but found no benefit. She also cited the CONCOR-1 trial, which studied nearly 1,000 patients in Canada, but it ultimately stopped accepting new patients after the treatment failed to improve patients’ condition.

Since the news broke, providers are increasingly giving up hope on convalescent blood plasma.

However, Dr. Arturo Casadevall at the Johns Hopkins Bloomberg School of Public Health isn’t ready to throw in the towel. The trials mentioned above focused on patients suffering from COVID-19 in the hospital. He believes the blood plasma should be used earlier in the infection process to prevent serious illness from emerging in the first place.

Dr. Casadevall is collecting data via a new clinical trial, but it’s been slow going. “From the very beginning here at Hopkins we set out to do outpatient trials. The trials were set up in March [of 2020], however it took many months to get the money to do it,” he says. The study is now gearing up, thanks to additional funding from billionaire Michael Bloomberg.

But, as it turns out, collecting blood plasma from people who have recovered from the virus can be next to impossible. The U.S. is made up of thousands of different companies and agencies. Getting them all to work together and share data isn’t always easy. One year later, Dr. Casadevall’s study has yet to show results.

Dr. Derek Angus, chair of critical care medicine at the University of Pittsburgh, thinks providers and scientists should have immediate access to patient and clinical information in order to examine the results in real-time, but that’s not how things work in the U.S.

“People might roll their eyes and say that’s impossible, but that’s largely what the United Kingdom has done. For all our capacity in the United States, it’s depressing that we can’t do a U.S. version. We pride ourselves on having a very federated, independent system. But, gosh, that is very hard to turn on a dime to solve national problems,” Dr. Angus said.

He says the U.K. uses a nationalized health system, which helped researchers collect and analyze data from patients regarding the new treatment. For example, the country set up a network of emergency room physicians who received federal funding to test the treatment in patients who were sick enough to be in the hospital but healthy enough to go home later.

“We should have been able to get this done as quickly as they did in the U.K. It was just a much slower process to set up,” says Dr. Kevin Schulman at Stanford University.

As for now, convalescent blood plasma seems to be stuck in the clinical trial phase, at least when it comes to COVID-19. Until providers can identify a specific group of people who stand to benefit from the treatment, it won’t be widely available any time soon.