In August, the Food and Drug Administration broadened its emergency use authorization (EUA) for convalescent plasma, which uses the antibodies in recovered Covid-19 patients’ blood to treat those still suffering from the disease. In a press release, agency officials called the blood product a “potential and promising Covid-19 treatment,” expanding access so any doctor can give it to any patient with a laboratory-confirmed case of Covid-19, not just to those enrolled in clinical trials.
Convalescent plasma has been used for over a century to treat diseases like measles and influenza. After patients recover from an infection, their blood is filled with antibodies: a small cellular army that is specialized to fight off a certain pathogen. Transfusing some of that antibody-rich blood to someone who is still sick with the same infection gives them a new platoon of soldiers, ready to help boost their immune system and fight off the disease. That plasma isn’t a vaccine, and it won’t train the new patient’s immune system how to fight off the disease. It could help keep the infection from escalating—but it may do nothing at all.
Data on the effectiveness of convalescent plasma for Covid-19 has so far been inconclusive, largely because of a lack of randomized controlled trials. FDA spokespeople have overstated the treatment’s effectiveness, and the timing of the agency’s EUA announcement, right before the Republican National Convention, fed speculation that the Trump administration pressured the FDA to issue the approval. Last week, a panel of experts at the National Institutes of Health refuted the FDA’s data in support of the EUA, saying there was no data from well-controlled clinical trials to support the hypothesis that convalescent plasma is an effective therapy. Some hospitals are even toying with the idea of ignoring the authorization and devoting plasma resources to more clinical trials instead.
Despite this controversy, demand for the plasma has remained unchanged. Staff at blood centers say it has been high for months and that need for the product corresponds to the rise in cases across the country more than it does to FDA announcements or to politics. As Covid-19 case rates spiked in June and July, so did requests for plasma. Today, blood centers are continuing to ramp up collection efforts, as hundreds of units are distributed nationwide every day. And they’re trying to get more donors in the doors, since supply is slim, especially for people with rare blood types.
At Bloodworks Northwest, which distributes blood to more than 90 hospitals in the Pacific Northwest, executive vice president of blood services Vicki Finson says that as cases ebb and surge, demand for the treatment follows suit. “It’s been pretty high lately, and we actually reached a point where we were having a hard time keeping up with demand locally,” she says.
Like many other blood centers across the country, Bloodworks Northwest started collecting convalescent plasma in April. At first, its staff was able to meet local demand and even to donate extra to the military and to the national supply, sending it to new Covid-19 hot spots as they popped up. But as cases surged over the summer, they could barely keep up. “We were right on the edge,” says Finson.
Similarly, the American Red Cross reported that demand for convalescent plasma more than doubled in July, reducing its inventory by about 70 percent. “Our demand just spiked incredibly,” says Pampee Young, the organization’s chief medical officer. The Red Cross was able to build up inventory over April, May, and June, but Young says as demand increased in late June, they didn’t have enough donors to match the need, depleting their stores. In April, the Red Cross issued 150 to 200 units of convalescent plasma every day. Now, it's issuing between 300 and 450 units daily and collecting 500 units from donors. “Things are looking better now,” she says. “We are slowly gaining inventory. Very very slowly.”
Both Young and Finson say that, if anything, the FDA announcement has encouraged more people to donate. In the days following the agency’s EUA notice, signups at Red Cross centers doubled and have stayed high. “We are encouraged,” says Young. She hopes that first-time donors will have a positive experience and that they'll come back again and again.
“We are seeing an increase in the number of blood donors stepping forward, which is great, because it helps the blood supply in general,” Finson agrees.
But banking up a supply is not as simple as finding willing donors. Blood donors have to be at least 16 years old, in good health, and weigh at least 110 pounds. They also can’t have certain diseases like HIV, hepatitis C, or some cancers. Some prospective donors taking medications like the acne treatment Accutane need to wait weeks or months for the drug to leave their system before they can give blood. Men who have had sex with men have to wait three months after their last sexual contact, and there’s also a three-month waiting period for people who have had certain sexually transmitted diseases, used nonprescribed intravenous drugs, or had sex with a person with HIV/AIDS. “The donors are like a needle in a haystack,” Young says. To provide convalescent plasma, she continues, “not only do you have to be well and qualify as a normal blood donor, but you also have to be recovering from Covid-19.”
And just as with donating for blood transfusions, convalescent plasma needs to be compatible with the recipient’s blood type. For people with common types, like O positive, there isn’t an issue: The Red Cross can usually meet their needs within a day or two. But for those with rare blood types like AB, who make up less than 4 percent of the US population, there isn’t adequate supply. Young says it can take five or six days to get these patients the right plasma.
The only way to increase inventory is to encourage more donations. New York Blood Center, which distributes blood products nationally, is collecting about 3,000 units every week, but executive medical director Bruce Sachais says their goal is to more than double that to 7,000. Similarly, Kate Fry, CEO of America’s Blood Centers (ABC), says the organization is ramping up national collection efforts. “We’re seeing collections able to meet patient demand, but we always need more donors,” she says. “We’re expecting demand to continue to go up.”
But while demand is rising, collections are getting harder. Blood centers get many of their donations from college, high school, and office blood drives, none of which are happening because of the pandemic. Fry estimates that 30 to 40 percent of ABC’s donations have disappeared because of office and school closures. Young of the Red Cross says the loss of those sites has had a “tremendous negative impact” on their collection efforts.
That means blood centers have to get creative about getting the word out. The New York Blood Center has partnered with staff at local hospitals who can refer recently recovered Covid-19 patients, and the Red Cross worked with university, state, and local officials to run public service announcement campaigns and virtual events on Facebook. Some agencies are also running pop-up collection centers for a couple weeks at a time in empty office buildings. Gulf Coast Regional Blood Center and Bloodworks Northwest partnered with local sports venues and teams like NRG Field, the Mariners, and the Seahawks to promote blood drives.
Those blood centers also decided to test every donation they collect for Covid-19 antibodies. Finson says they’ve tested over 7,000 donations and that about 2 percent of those test positive for antibodies, meaning they can be used as convalescent plasma. “That’s a fair number of units,” she says. If a unit tests positive, Bloodworks Northwest will contact the donor and encourage them to come back to donate again. “Our goal is to build up at least a five- to six-week inventory so that we are prepared,” says Finson. “This testing has helped.”
Changes in FDA regulations are helping, too, by making it easier for donors to give plasma more often. Instead of waiting 28 days, convalescent plasma donors can now give plasma once every seven days.
And while national attention has turned to convalescent plasma for Covid-19, employees at blood centers add that the need for regular blood remains high. Many patients with other health issues postponed elective surgeries and procedures because of the pandemic. But they can’t defer care forever, and many of those medical appointments are starting up again. "I think the thing we need to remind people is the need for blood is ongoing,” Finson says. “We’re still transfusing at a higher than normal rate, and that’s because there’s a backlog of people."
“The message is: donate,” she continues. “And if you’ve had Covid and you’re fine now, really think about coming and donating.”
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