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Convalescent plasma has been used to fight many infectious diseases, from scarlet fever in the 1930s to whooping cough and measles and, in more recent times, swine flu, Ebola, and Middle East respiratory syndrome.

The idea seems to make sense: The plasma of people who survive these diseases contains antibodies that may have helped them survive. When their plasma is donated and the antibodies are isolated from it and transfused, it could perhaps help newly infected people survive as well.


The problem is that no one is sure whether convalescent plasma works. In the face of a largely incurable disease like Ebola, some doctors, desperate to do something for a dying patient, try this approach without studying it. They engage in what I call “panic prescribing,” leaving the world with no idea if convalescent plasma does anyone any good or not.

President Trump has joined the panic prescription response to Covid. At a press conference on Sunday he said it was “proven to reduce mortality by 35 percent.” He said that even though the study being referred to did not have a control group. Even worse, 35% was an improvement in a select group of patients infected for fewer than three days. Few get any serious care that quickly. And worst of all, 35% refers to the improvement over survival given current supportive care efforts, which usually fail — not an absolute jump of 35% overall survival.

The president proudly made his announcement on the basis of weak data showing marginal improvement in a small segment of Covid-19 patients. He strong-armed scientists working in the federal government to open the floodgates for using convalescent plasma under an emergency use plan. This came only one week after scientists at the Food and Drug Administration and the National Institutes of Health had looked at the same evidence and declined to let doctors try convalescent plasma without getting better evidence that it does anyone good. The fact that it came a day before the start of the Republican National Convention tells a story all by itself.


Convalescent plasma appears to be fairly safe, but there are risks, as there always are with transfusions of blood products. No one who actually knows about the treatment is sure whether or why it works.

What Trump did not say, nor did officials from the FDA and the Department of Health and Human Services admit, is that no one knows how much plasma to give, who is a good donor, when is the best time in the disease course to transfuse convalescent plasma, how much, if any it actually improves survival, who are the best candidates for convalescent plasma, and whether it should be tried in combination with other therapies.

There are no careful peer-reviewed randomized trials of convalescent plasma for Covid-19 even though nearly 100,000 people in the U.S. have gotten it since March.

One group that knows how little we understand about convalescent plasma for Covid-19 is the Infectious Diseases Society of America. Here’s what its president, Dr. Thomas File, said in a statement (bolded emphasis his):

“While the data to date show some positive signals that convalescent plasma can be helpful in treating individuals with Covid-19, especially if given early in the trajectory of disease, we lack the randomized controlled trial data we need to better understand its utility in Covid-19 treatment. For this reason, IDSA supports the continued collection of data in randomized clinical trials to better understand the benefits of convalescent plasma treatment before authorizing its wider use in patients with Covid-19.”

In other words, President Trump has no basis for giving carte blanche for the use of convalescent plasma. Heads of the FDA and HHS, who do know better, got ordered to smile and nod in agreement with Trump’s convention surprise, lest they get tarred as deep state obstructionists. The rush should be trying to figure out if convalescent plasma really works, but the president has made that impossible since no trials will get funded or enrolled. Instead, the future holds vicious infighting as doctors struggle to grab some of the scarce supply of convalescent plasma for their patients, since the president has all but announced it as a cure.

The promotion of convalescent plasma shows once again that nothing but politics drives Trump’s response to the Covid-19 pandemic. He has made it clear that scientists who oppose him in the once highly respected FDA, CDC, and NIH will have no standing if they deviate from his agenda. And he has signaled that he will not hesitate to promote a vaccine as ready to go — data be damned — if he needs an October surprise to salvage his political future.

Despite Trump’s decision to promote it, we will be no closer to knowing if it works, for whom, and how best to use it — knowledge that should have preceded any emergency use authorization for convalescent plasma. Once emergency use is permitted, the ability to do clinical trials to answer these questions is put in extreme jeopardy.

Convalescent plasma will now rapidly become the treatment of choice for those rich enough, connected enough, and lucky enough to access it. It is in very short supply. So doctors, besieged by patients and families to use it on their loved ones based on the publicity, will resort to panic prescribing. Who will get this scarce resource? Emergency use is usually not covered by third-party payers. So, the rich will likely be first in line.

Panic is not the way to identify treatments for Covid-19. President Trump’s disdain for science and medicine in favor of politics is not likely to matter much to improving the fate of the victims of Covid-19.

Arthur Caplan is professor of bioethics and the founding head of New York University School of Medicine’s Division of Medical Ethics.

  • Medical (Democratic leaning) community plays fast and loose with data – number of infected people vs deaths. But when it comes to potentially moving forward on this disease the pull out the requirements for arduous peer reviewed randomized trials. Your politics is pretty obvious and biased

  • Spoken like a true democrat who will do anything to keep the sick from recovering There is enough data to suggest convalescent plasma works. I’m tired of politics
    If you were sick you’d be the first inline to request it. Hypocrites

  • Stop wasting time! 800k people are dead and literally the only drug that has convincing RCT results of reduced mortality is dexamethasone. That is frankly pathetic 7+ months after the isolation of this virus as the cause of the Wuhan pneumonia outbreak.

    A retrospective matched cohort analysis of the tens of thousands of people given convalescent plasma vs. tens of thousands of similar patients not given the treatment (matched for age and other co-morbidities) should be more than sufficient evidence that convalescent plasma works when given EARLY in the disease course.

    We already know through countless smaller observational studies that convalescent plasma is generally safe and well tolerated. The Mayo clinic results which demonstrated dose dependent statistically significant differences in mortality and treatment time dependent statistically significant differences in mortality provide a strong basis of evidence for efficacy for anybody who lives in the real world where nothing is completely without risk.

  • This story is political rather than medical. If we had leisure time to react – a study would be great. But these are times of emergency. The author does not understand EUA. That you would withhold a cure or medicine from someone in a double blind study is obscene- remember the Tuskegee airmen and the syphillis experiment- did you think that was ethical too? Improvement in 35% when given early is a good outcome. More studies can be done while in progress but this isn’t a new process in medicine, having been used for other illnesses.

    If Joe Biden said we should use it, he’d be praised. But this is Trump and he is damned if he does, damned if he doesn’t. This article is just political commentary. Let Mr Caplan be the guinea pig in the group that doesn’t get the convalescent plasma.

    • Please learn your history about the Tuskegee experiment. It wasn’t the famous airmen who took part; it was the poor Black men in that area. They were denied a proven cure for syphilis (that was available at the time to white people in the area) so that their tertiary disease could be studied, or until they died. There is no data that shows that convalescent plasma cures COVID-19, or that people are being denied any treatment here when a definitive cure is known. Please focus on the science, where the relative benefit was about 3%, and don’t misquote what history has shown us. Check out the book Bad Blood by James Jones if you’d like to learn more about the horrific Tuskegee studies.

  • I am glad to see that we will be using convalescent plasma. This is about hope. What America needs now is hope. Your story is all doom and gloom and about attacking the president. Sometimes you do not have time to jump through all of the hoops before deciding to save a life. If it were you dying of covid, I’ll bet you would be ready to use something that “might” work instead of just laying down and doing nothing. You slammed hydroxychloroquin and it is safely being used all over the world but the FDA has banned the use here. That is strictly political.

  • As a medical professional I continue to be appalled at the current administration’s putting politics ahead of science and the national welfare’s every turn. Even if this treatment is effective the supplies are very scarce and it will be extremely expensive, not covered by insurance, and therefore only available for those who can afford to pay huge sums out of pocket. Since the poor and people of color are the majority of those currently infected with COVID-19 this means we will be harvesting the blood of the poor to treat the rich, which is perhaps the most quintessential Trumpian response to our national tragedy yet.

    • If it does work, how do you know that people with money won’t fund it? Lots of people have given millions of dollars to help others. Class warfare, racist propaganda and lack of any positive thought for the future is a lack of focusing on answers and care for others. As I come from a mixed cultural and racial family, it grows tiresome to hear that we are all hurting those of other colors. Please speak for yourself.

    • Why would you think that CCP would only come from POC or poor? You know little about collecting plasma. It’s called a donation – it isn’t paid for – and there was a call across America for ALL who can to donate to give their plasma

      You should volunteer to be in a double blind study. But if you get sick, ask for the placebo.

      It is unethical to withhold treatment from a patient when it can help him/her. It isn’t political.

    • And yet when a local doctor was ill he say that he was give blood plasma, remdesivir and dexamethasone and within hours started to feel better. This country needs some hope people. Hopelessness kills as well. As an older citizen they have scared with no hope of any treatments. Perhaps if one of your loved ones get ill you can offer them a placebo. Even if this helps only one patient it is well worth it. This pandemic has only helped our politicians to keep our citizens divided. We should all realize we are all pawns in their game. It breaks my heart to see so many people hating each other. Wake up we need a system overhaul, they all need to go. They have no clue what the citizens of this country go through just to put food on their table.

    • It is an opinion piece but the facts stated in it are true. One fact you apparently missed was his point that we don’t have enough data yet to know whether plasma is an effective treatment or not, therefore no one can give an evidence-based argument for or against it.

    • Patricia,

      You forgot about the Emergency Use Authorization. You don’t need a complete set of data in order to issue a temporary authorization.

      I hope you go back and study before coming on here and spitting nonsense.

  • Does anyone remember the last big cure, hydroxychloroquine? It was promoted in much the same manner by the president. Millions of doses were purchased for the national stockpile, and today, COVID-19 infections are still rampant, Americans are still dying or being disabled by the disease, the cost of treating patients with the illness is astronomical, and no one seems to be using the president’s cure anymore? Isn’t that curious???

    • HydroxyChloroquine is a nonlethal drug. The media and the democrats are against it. It is politicized by them. The Lancet journal had to withdraw a publication due to bad study against HydroxyChloroquine. This publication caused the FDA to stop the HydroxyChloroquine trial.

      Amy Klobuchar’s husband was treated with HydroxyChloroquine. However, the democrats are against it because they don’t want to give Trump a win.
      They rather kill Americans than concede to Trump.

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