Fact-check: Dr. Stella Immanuel’s hydroxychloroquine cure

By Kristen Panthagani, PhD

This morning I got a request to address one of the latest viral videos going around from a doctor claiming that we already have a cure for COVID-19: hydroxychloroquine, azithromycin, and zinc. While the video has been taken down on many platforms (and for the record, I have very mixed feelings about this type of censorship — that is a whole other discussion), it has rekindled the hydroxychloroquine fire set by Dr. Raoult back in March, the idea that hydroxychloroquine is the silver bullet for COVID-19, and all these masks and lockdowns are unnecessary. So let’s take a look at her claims and see if what she’s saying has any merit.

Her basic arguments are this:

1. She has treated over 350 COVID-19 patients with hydroxychloroquine + azithromycin + zinc, and none of them have died, therefore this treatment is a cure.


2. She and her staff and some other doctors have been taking this drug combo as prophylaxis and none of them have gotten sick, therefore it is also effective as a prophylaxis.

She then goes on to say that any study saying otherwise is fake science, it’s unethical not to give the drug now because people are dying, and doctors who are standing by, and not giving this treatment are like the ‘good Germans’ who stood by and let the holocaust happen. We’ll tackle some of these follow-up claims in a minute, but first let’s look at her dataset that she is basing these claims on.


Her argument is that treating 350 COVID-19 patients and all of them surviving is evidence that the treatment is a cure. Usually we want a control group to compare to, but it seems Dr. Immanuel believes this would be unethical, so we have none. This is big flaw #1 of her data set. But, let’s work with we what we got: whenever we look at any outcome in science, we always first look to see what is the probability of getting that outcome by pure chance. So what is the chance of having 350 COVID-19 patients in a row all survive? While the COVID-19 mortality rate is a tricky number to nail down, let’s use an estimate of 1% (i.e. on average, across the entire population, 1% of people who contract COVID die from it). If we look at 350 COVID-19 patients at random, the chance of having every one of them survive is (1-0.01)^350 = ~3%. Seems small right? Not necessarily — if we consider the fact that millions of people are getting this disease all across the country, the chances of this happening at least once becomes quite large. As of today there are ~4.38 million total confirmed COVID-19 cases in the US — if you broke all of those people into groups of 350 patients (that’s about ~12,000 groups of 350 patients), we would expect ~360 of those groups to be all patients who survive. So this result is expected to happen by chance 360 times across the US. This indicates her data set really isn’t strong evidence of anything, as the chances of this happening aren’t too improbable when you are looking at a disease that is so prevalent across the US.


But, as everybody knows, the mortality rate is highly dependent on the population you are looking at. So what patients is she treating? Are they representative of the average population? Is 1% mortality a reasonable estimate for them?


To listen to her talk, you might think she is working in a hospital taking care of very sick COVID-19 patients and miraculously seeing them all get better with the hydroxychloroquine combo. But she keeps using the word “clinic”.. which is not where sick hospital patients are treated. ‘Clinic’ generally refers to an outpatient doctor’s office or perhaps an urgent care center. So what “clinic” is she talking about?


After doing a little googling, I found that she works at Rehoboth Medical Center, which, though the name sounds like it might be a rather large medical operation, is in fact a walk-in clinic in a Houston strip mall.

Google street view of strip mall with “Rehoboth Medical Center.” This seems to be the right image — it matches the video on the clinic’s facebook page, where the name of the medical center appears to be added electronically.

Edit: earlier version of this post included an image a few shops down, which is what google pulls up for “Rehoboth Medical Center.” However, based on closer review of the clinic’s facebook video, I believe this is the correct image of the clinic.


So these are 350 COVID-19 patients who came to her walk-in clinic. This very much skews her data set. First, it means that the people she is studying are not very sick patients (because they are going to a walk-in clinic for treatment, not a hospital.) This is confirmed by the video on the clinic’s facebook page, where she says they “screen and treat mild cases of COVID-19.” The chances of having 350 mild COVID-19 patients all survive is much, much higher than the chances of 350 very sick hospitalized COVID-19 patients all survive. Second, and perhaps more problematic, it is unlikely that she is able to follow-up with all of her patients to see whether they did well or not. Is she regularly calling all the patients who came to her clinic to see if they went to the hospital and died? I guarantee you medical records are not coordinated enough for her to follow up with them that way. If she has a patient who comes in on Tuesday, gets his hydroxychloroquine/azithromycin/zinc combo, then falls very ill on a Friday and goes to a hospital across town, how would Dr. Immanuel know? Unless she is faithfully following up with every walk-in patient and has backup plans if those patients become too sick to speak on the phone, it is unlikely she could rigorously track whether or not her patients became sick and died. So in essence, it seems like Dr. Immanuel may be saying that nobody died at her walk in clinic, or called to let her know that one of her patients died. The fact that this happened for 350 people in a row now becomes highly, highly probable, not improbable.


And now her prophylaxis argument. She adds that masks are not necessary because we already have a COVID-19 prophylaxis: hydroxychloroquine + azithromycin + zinc. It is a little confusing watching the viral video of her making this claim and then watching the video on her clinic’s facebook page where she is encouraging everyone to wear masks, stay 6 feet away, and use hand sanitizer. But, let’s address her argument. She argues that because herself and her staff and some other doctors have used the hydroxychloroquine drug combo as prophylaxis and they haven’t gotten sick, that proves that the drug is effective as a prophylaxis for everybody. But how many staff does she have? Based on the picture of the clinic, this is a fairly small operation, and they likely only have a few staff. Maybe ~10 staff work there. That is a very small data set to make such a bold claim. She said ‘some other doctors’ are taking it too… how many other doctors is she referring to? We can only guess, but let’s say it’s as many as 20. The chances of 20 health care workers not getting sick from COVID, if they are wearing masks and other PPE as the staff in her clinic are in the video, is not that small.


In summary, her “evidence” that hydroxychloroquine/azithromycin/zinc is a cure and prophylaxis for COVID-19 does not hold up at all. We would expect these same results by pure chance.


Now let’s look at the details of a few of her other claims.


She argues there is a 2005 NIH study that says ‘it works.’

While there are numerous in vitro studies looking at the effect of hydroxychloroquine on various viruses, I guarantee you that whatever 2005 study she is referring to was not studying SARS-CoV-2, as the virus did not exist back then. I’m not sure what study she is referring to (perhaps it was this 2005 in vitro study of chloroquine efficacy against SARS), but please remember that different types of studies carry different levels of weight. In vitro studies are considered very, very preliminary, and you can’t conclude a drug works in humans just because it worked in an in vitro study.


She says the NIH knows that hydroxychloroquine works because of a COVID hiccup study. “If the NIH knows that treating a patient with hydroxychloroquine proves that hiccups is a symptom of COVID then they definitely know that hydroxychloroquine works.”

She says to google hiccups and COVID to see what she is talking about, so I did. This is the study that came up: it is a case report (description of a single patient) of a man in China who presented with hiccups as an atypical presentation of COVID. That man was given hydroxychloroquine, and his hiccups did go away. However, I hope this doesn’t need to be said — this is not a study, it’s a story about what happened to a single patient. You can’t make sweeping conclusions about the efficacy of a drug based on one patient. If that were true, then any single patient who got the hydroxychloroquine drug combo and died would be evidence that it’s 100% lethal. This is considered anecdotal evidence and is not proof of anything.


She says she sees people sitting in her office knowing that this is a death sentence.

This is a very dramatic claim for someone who treats mild COVID patients. Not everyone who gets COVID-19 dies. Yes, an upsetting percentage of them do… but “death sentence” is over the top.


She says there is no way she can treat 350 patients and they all live, but other doctors/scientists are going to tell her that they treated 20 people, 40 people and it didn’t work.

This, I believe, is her criticism of other studies showing that hydroxychloroquine doesn’t work, which she asserts are fake science. She seems to be arguing that she has the biggest study of hydroxychloroquine effectiveness, and that studies of 20 – 40 people aren’t strong evidence to show lack of efficacy. While she is correct that studies of 20 – 40 people aren’t very strong evidence, she is mistaken in thinking that this is the sample size of hydroxychloroquine studies to date. Here is a randomized controlled trial of 4716 patients showing no benefit of hydroxychloroquine treatment, and here is a meta-analysis of 26 different studies (including a total of 103,486 patients) showing no clinical benefit of hydroxychloroquine treatment (with or without azithromycin). These are two of the strongest studies we have on hydroxychloroquine for COVID-19 to date. Check out this post for more details, as well as other published studies on hydroxychloroquine +/- azithromycin for COVID-19.


She says you don’t need masks — there is a prevention and a cure.

Again, her data “proving” that the hydroxychloroquine drug combo works as a prophylaxis is based on herself and her staff and some unknown number of other doctors, which is not very many people. Here is a randomized double-blinded placebo-controlled trial of hydroxyhcloroquine prophylaxis (studying 821 people) demonstrating that hydroxychloroquine prophylaxis did not protect against COVID-19. Check out this post for more details on hydroxychloroquine prophylaxis studies.


She says that for all the doctors waiting for data — if 6 months down the road they find out the drugs work, its unethical not to have treated them now. She also compares doctors standing by watching patients die to the ‘good Germans’ standing by letting the holocaust happen.

No. First, we already have lots of data on hydroxychloroquine and COVID-19, and there is not strong evidence to suggest it works against COVID-19 (see studies in previous paragraphs). But even if we didn’t have this data yet — that doesn’t mean it would be unethical to withhold hydroxychloroquine treatment until we know if it works or not. The way doctors decide whether or not to give any treatment is by weighing the benefits versus the risks. For benefit, we look at the evidence that the drug works (which is very little). For the risks, we look at the side effects (which include risks of heart problems). If you have a drug that lacks evidence that it works and has side effects, it is not unethical to avoid prescribing it.


In conclusion, this doctor is making claims based on a deeply flawed data set and ignores the other studies on hydroxychloroquine that contradict her conclusions. This is not helpful. I am not sure why she is doing this — it is very possible that she genuinely believes what she is saying and is trying to get the word out. But that doesn’t make her arguments valid.


Disclaimer: This blog is intended to help people understand scientific concepts and is NOT intended to provide medical advice. Please consult with your physician for any questions about health concerns or medical treatments. The American College of Physicians’ statement on hydroxychloroquine for COVID-19 can be found here.


Edit: But what about the Yale epidemiologist’s Newsweek article calling hydroxychloroquine the key to defeating COVID? Read about that here.

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