Computing Forever interview with Dolores Cahill contains numerous inaccuracies about COVID-19 and vaccines

This video, first published on 11 May 2020, features an interview between Dave Cullen, also known as Computing Forever on YouTube, and Dolores Cahill, a professor at University College Dublin who specializes in proteomics and also the chairperson of the political group the Irish Freedom Party. Lasting about an hour, the video rehashes previously-debunked misinformation about COVID-19 and vaccines, and received more than 500,000 views. While the original video has since been removed from YouTube for violating the platform’s policies on misinformation according to a report by Business Insider, copies continue to be uploaded on multiple social media platforms, and these copycat posts have been viewed more than 150,000 times over the past two weeks.


Claim 1:

Cahill: “What I want to publicize is, it’s well known in immunology, you can take preventive measures to boost your own immune system, so that even if you were a little bit malnourished or rundown, that if you take vitamin D, vitamin C, and zinc, your immune system will be boosted, and also if you eat—good nutrition—so that if you come across the virus […] you will have hardly any symptoms, you will clear the virus.

Cahill is correct that good nutrition is vital to maintaining health and ensuring that one’s immune system is functional. However, the notion that a person can consume certain nutrients to “boost” the immune system can be misleading. As Health Feedback explained in a previous review, Vitamin C supplementation helps reduce the risk of respiratory infections, according to a 2012 Cochrane review, but this effect has been observed only in individuals experiencing severe physical stress, such as marathon runners, and not in the general community.

Similarly, Vitamin D supplementation also has a protective effect against respiratory infections, but this effect is most prominent only in people who are vitamin D-deficient, as another review by Health Feedback showed. With more than 40% of Americans estimated to be vitamin D deficient[1], many scientists and health officials have recommended vitamin D supplementation as a way to reduce the risk of SARS-CoV-2 infection[2]. This is based in part on a 2017 meta-analysis of studies involving a total of 11,321 participants which found that daily or weekly supplementation with vitamin D reduced the risk of acute upper respiratory tract infections in all participants, and that the protective effects were stronger in individuals who were previously vitamin D deficient[3]. However, none of these studies has specifically tested the effects of supplementation on COVID-19 patients.

Zinc is important for enzyme function and deficiency can lead to poorer immune function. According to the U.S. National Institutes of Health, zinc deficiency is uncommon in the U.S., although there are certain groups in the population at risk for zinc deficiency, such as people with gastrointestinal disorders, pregnant and lactating women, as well as vegetarians.

In other words, vitamin and mineral supplementation are helpful in maintaining immune function, but beneficial effects are generally only observed in cases where a deficiency is already present. A person who is consuming a balanced diet with optimal levels of nutrients is unlikely to receive “immune boosting” benefits from supplementation. The British Society for Immunology has explained that:

The evidence that you can boost your immune responses by doing something or taking supplements or eating a certain food is elusive and makes little scientific sense. The immune system is your body’s built-in defence system to protect you against harmful bacteria and viruses and it carries out this function very well most of the time.

If you could boost your immune system and it’s working well already, that might make you more ill. Immune overactivity is as dangerous as immune underactivity. For example, an overactive immune system (which attacks inappropriate substances such as pollen grains or your own body’s cells) causes conditions such as allergy and autoimmune diseases like rheumatoid arthritis. Living a healthy, balanced lifestyle is the best thing you can do to make sure your immune system can function optimally.

Claim 2:

Cullen: “Your natural flora, the bacteria, the things that we’re always transmitting—we’re always transmitting these things to each other—mostly we’re asymptomatic and this is actually, you know, ‘what doesn’t kill you makes you stronger’ kind of thing, this is actually improving our strength, but with this social distancing—because I can’t stand next to you and you can’t stand next to someone else, we’re not transmitting these diseases.”

This is a reference to a video interview with two doctors from Bakersfield, California, that went viral in April 2020 and which Health Feedback previously reviewed and found to contain many inaccuracies. In this interview, Daniel Erickson, physician and owner of a chain of urgent care clinics in Bakersfield, claimed that sheltering in place would lead to a weakening of the immune system, because it would limit exposure to “normal bacteria and normal flora”. While it is correct that healthy development of the immune system requires exposure to microorganisms like bacteria, fungi, and viruses, sheltering in place would not minimize exposure to microorganisms to the extent of causing immune dysfunction.

As Steve Lee, associate professor at Loma Linda University’s School of Medicine, explained in a Facebook post, “Unless you live inside a bubble, your home and your yard have TRILLIONS of pathogens. No amount of lysol and handwashing is going to remove pathogens that you breathe in and touch all the time. Your own mouth has billions of microbes. Your skin is teeming with microbes. Fungal spores and viruses [are] in the air.”

Jennifer Kasten, assistant professor of pathology and cardiology at the University of Cincinnati, also refuted this claim in a Facebook post. “Unless you live inside an autoclave, your home is plenty pathogen-rich,” she wrote. “The world is absolutely teeming with microbes. You’re coated in them, your house is coated in them, they enter your body with every breath you take and everything you eat. Your immune system is getting a perfectly adequate workout. You’re just restricting your exposure to a handful of things (respiratory pathogens) for a very short period of time.”

Claim 3:

Cullen: “Percentage-wise [COVID-19 has] only between 0.1 and 0.3 fatality.”

This is inaccurate and imprecise. Preliminary studies have estimated a wide range of values for the infection fatality rate (IFR) of COVID-19, which is the fatality rate from both lab-confirmed cases and estimated undetected cases, between 0.2 to 1.6%[4]. As a reference, the flu has been estimated to have an IFR of about 0.04% according to Christophe Fraser, an epidemiologist at the University of Oxford.

The case fatality rate (CFR) of COVID-19, or the fatality rate among only lab-confirmed cases, has been estimated to be between 2–8% based on a review of the previous literature by Verity et al., although their own analysis yielded an overall CFR of about 1.4%[4]. Epidemiologists were also able to obtain a robust CFR estimate of 0.99% on the Diamond Princess cruise ship[5] due to the small population size and quarantine status of the passengers, which enabled scientists to closely track infected, uninfected, and asymptomatic passengers alike.

Cullen did not specify whether he was referring to the CFR or IFR, but on both counts, the estimates he provided was inaccurate.

Claim 4:

Cahill: “SARS virus circulated [since] 2003 and essentially every three or four years since, so that people are immune—so that everybody practically in the world is immune.”

This claim is inaccurate. The global outbreak of severe acute respiratory syndrome (SARS) began in November 2002 and ended in July 2003. The SARS virus has not circulated widely since then. Apart from a re-emergence of SARS in December 2004, which was limited only to China, specifically nine cases in Beijing and the province of Anhui, no other cases of SARS have been reported. The SARS outbreak led to more than 8,000 infections, which is only a tiny fraction of the world’s population, hence Cahill’s claim that “everybody practically in the world is immune” is baseless, as the vast majority of the world’s population has not been exposed to the SARS virus and therefore cannot have developed immunity to the virus.

Claim 5:

Cahill: “So when they reported in the California study, in the Bakersfield study, with Dr. Erickson, it turned out the percentage [of the population that is infected with COVID-19] was around 7% right? So globally the people have antibodies in general, whether for COVID-19 or not, that would test positive in these things—it’s between 7% and 15%. But it just means the other people don’t have antibodies that are detectable or they don’t need to develop antibodies, because they’re not attacked by these viruses and they don’t have any symptoms.”

Pointing to data from COVID-19 testing in their clinics, Erickson said that they had conducted 5,213 tests and found 340 positive results, or approximately 6.5% positive results. He then extrapolated this percentage of positive results to estimate COVID-19 incidence in the entire population of the state of California, and concluded that “this equates to about 4.7 million cases throughout the state of California”.

Several physicians and scientists have pointed out the problem with Erickson and Massihi’s estimates and extrapolation, which Health Feedback reported in a previous review. Specifically, the sample population they used was non-random and produced biased results. Experts have drawn analogies to illustrate the problem with the duo’s approach:

Estimating the fraction infected from patients at an urgent care facility is a bit like estimating the average height of Americans from the players on an NBA court. It’s not a random sample, and it gives a highly biased estimate.

Carl Bergstrom

Walk around an ER on a Friday night. If 4 out of 50 patients had broken legs, and another 10 had heart attacks, you can’t assume 8% of the city fell off a ladder when drunk that night and a full quarter were clutching their chest in an armchair as we speak. In epidemiology terms, that’s selection bias—bias introduced by a non-random sample.

Jennifer Kasten

This kind of thought process would be like I run an emergency room and tonight 10% of the people have a stroke. Then I extrapolate that to mean that 10% of the world is having a stroke tonight. That’s obviously ludicrous. The sample of people coming to the ER is not representative of the entire population.

Steve Lee

Cahill’s claim that “people have antibodies in general, whether for COVID-19 or not, that would test positive in these things” would in fact render the results that she cited invalid, as this would mean that the tests are not specific for COVID-19 antibodies. This is inaccurate—the tests for COVID-19 are specific to the antibodies produced against the disease. Furthermore, the presence of antibodies to other pathogens would not generally confer protection against COVID-19.

The claim by Cahill that people “don’t need to develop antibodies, because they’re not attacked by these viruses” is illogical. While people who are currently not infected do not develop antibodies against SARS-CoV-2, this does not mean that people who test negative are somehow naturally immune to the virus or that an infection will not occur at a later time.

Claim 6:

Cahill: “Hydroxychloroquine […] was shown […] by doctors worldwide to be the most efficient treatment for the coronavirus.”

The claim that hydroxychloroquine has been shown to be the most efficient treatment for COVID-19 is unsupported. As Health Feedback explained in a previous review, recent studies purporting to show the effectiveness of hydroxychloroquine for COVID-19, which have received significant media attention, are flawed in design, as they lack the necessary controls and information about how patients were recruited. More rigorous clinical trials, such as the World Health Organization’s Solidarity trial, are now underway to assess the effectiveness of hydroxychloroquine. As the results of these trials are not yet available, Cahill’s claim is premature.

Cahill’s description of the doctors’ poll on the effectiveness of hydroxychloroquine is also inaccurate. This fact-check by Full Fact explained that the poll was not representative of doctors worldwide and only 37% of the 6,227 doctors surveyed actually said that hydroxychloroquine is the most effective coronavirus treatment.

Furthermore, on 24 April, the U.S. Food and Drug Administration (FDA) cautioned against the use of hydroxychloroquine or chloroquine for COVID-19 outside of a hospital setting or a clinical trial due to risk of heart rhythm problems. In a statement, the FDA announced that “Hydroxychloroquine and chloroquine have not been shown to be safe and effective for treating or preventing COVID-19” and that “Hydroxychloroquine and chloroquine can cause abnormal heart rhythms such as QT interval prolongation and a dangerously rapid heart rate called ventricular tachycardia.”

Claim 7:

Cahill: “There’s been papers published by the U.S. Army, where they have certain flu vaccines in 2017 and 2018 given to soldiers, that when they naturally come across a coronavirus, they have a cytokine storm and are severely sick. So it turns out in the vaccines that were given in Wuhan and in Italy, in the Lombardy region, … these vaccines have been grown on dog tissue and dog tissues are known to have coronaviruses.”

Cahill is likely repeating a claim made by Judy Mikovits in the “Plandemic” video, which also contained numerous false claims about COVID-19, which Health Feedback previously covered here. Mikovits claimed that the high COVID-19 death toll in Italy was due to the use of flu virus strains grown in a cell line derived from a cocker spaniel, called Madin-Darby Canine Kidney cells, in flu vaccines. Since 2012, this method of flu vaccine production has begun to complement the more traditional method of virus production in chicken eggs. Neither cell-grown nor egg-grown flu viruses used to make flu vaccines have been shown to contain coronaviruses or any other foreign viruses from other animals, including dogs. Nor have flu vaccines been proven unsafe in healthy individuals.

While there are strains of coronavirus that infect dogs, SARS-CoV-2 has been shown through phylogenetic analysis to most strongly resemble a bat coronavirus named RaTG13, with 96% genome sequence identity[6], so it is not clear why Mikovits drew a causal relationship between canine coronavirus and COVID-19. Mikovits did not provide any evidence that cell cultures used in making the flu vaccine are contaminated with coronavirus, whether of bat or dog origin.

Claim 8:

Cahill: [Vaccines are] “not safety tested and a lot of the ingredients that are in vaccines are known themselves to actually be bad for the immune system, like aluminium or mercury, so there is absolutely no necessity for those kind of toxic ingredients to be in vaccine adjuvants at all.”

Contrary to Cahill’s claim, vaccines are tested and continually monitored for safety. The U.S. Centers for Disease Control and Prevention (CDC) continually updates information regarding vaccine safety, including publishing safety reports and information on side effects.

Only three types of adjuvants, including non-toxic aluminum salts, are approved for use in the U.S. They are used to heighten the immune response upon vaccination and enhance protection during subsequent natural infection. Scientists who commented in reviews by Health Feedback here and here explained that the quantities of aluminum adjuvants used in vaccines are safe.

Contrary to Cahill’s claim, mercury is not used as an adjuvant, although thimerosal, a mercury-containing compound is often added as a preservative and antibacterial. Thimerosal is also a non-toxic compound that is quickly and safely metabolized by the body.

Vaccines are safe and vaccine ingredients at the doses and formulations used are not associated with toxicity, as Health Feedback explained in previous reviews here and here.

Claim 9:

Cahill: “It’s been known for like sixty years that just simple mineral-type oil is plenty antigenic for the body to elicit an immune response, you do not need to be adding in human DNA, mercury, aluminium.”

This is misleading. Mineral oil is a component of a certain type of adjuvant, called Freund’s adjuvant, that is used only in vaccine research. Its use in humans is forbidden by regulatory authorities due to toxicity, as it triggers excessive immune responses which lead to tissue damage[7]. No human DNA is added to vaccines.

Claim 10:

Cahill: “There is no need for social distancing. There are only three organisms that are transmitted in that way, and it’s TB and smallpox and Ebola, so this one is not. This one is transmitted if a droplet is on a door handle.”

It is biologically plausible for SARS-CoV-2 to be transmitted through surfaces contaminated with infectious respiratory droplets (fomites). However, SARS-CoV-2 can also be transmitted through airborne respiratory droplets that carry the virus. As explained in this Health Feedback review, these aerosols can be generated by coughing, sneezing, or even just talking. Respiratory droplets have been identified as the main mode of COVID-19 transmission.

Droplets from speech have been shown to stay in the air between eight to 14 minutes[8]. Infectious respiratory and speech droplets can also be generated by people who are asymptomatic or pre-symptomatic, that is, not showing any sign or symptom of disease[9]. Social distancing can therefore curb the chain of transmission by minimizing contact with and proximity to those who are infected but do not show symptoms.

Claim 11:

Cahill: “What a mask does, it’s entirely the wrong thing. It actually reduces the oxygen supply to you, so actually everybody has latent viruses within their body, and because you’re under oxygen stress, it allows viruses that were latent—because you’re under stress it decreases your immune system.”

This claim, which has little to no scientific basis, went viral recently on social media platforms. As Health Feedback explained in a previous review, the use of a face mask does not result in hypoxia (low oxygen levels) in healthy people, nor does it weaken the immune system.

Furthermore, the CDC recommends that the general public wear cloth face coverings to slow the spread of COVID-19. The agency does not recommend that the public use face masks, such as surgical and N95 masks, which are in short supply and should be reserved for healthcare workers who are more frequently exposed. There has been no demonstrated negative effect of the use of face masks by medical personnel, which suggests that even the types of masks that utilize more restrictive air filters do not significantly limit the flow of oxygen to the people wearing them. However, the CDC has cautioned that “Cloth face coverings should not be placed on young children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated, or otherwise unable to remove the mask without assistance.”

Claim 12:

Cahill: “[COVID-19 patients become] immune for life and will no longer transmit the disease.”

This claim is unsupported. Whether COVID-19 patients who have recovered have lifelong immunity has yet to be established, and obtaining the data needed to determine this will take a significant amount of time. However, we do know that immunity to coronaviruses which cause the common cold is quite limited. Paul Hunter, professor of medicine at the University of East Anglia, said in this BBC article that “Based on antibody studies in SARS, it is possible that immunity [to SARS-CoV-2] will only last about one to two years, though this is not yet known for certain.”

Claim 13:

Cahill: “Hydroxychloroquine will work for all these types of viruses, these coronaviruses.”

This claim is unsupported. Hydroxychloroquine has been shown to be effective for diseases such as malaria and lupus. However, it is not a standard treatment for coronavirus infections, nor has it been shown to be an effective treatment for coronavirus infections. A similar claim that chloroquine, which is similar to hydroxychloroquine, works for all coronaviruses was misleadingly based on only a single in vitro study of chloroquine’s effectiveness at preventing SARS-CoV-1 infection in cell cultures, as this Health Feedback review explained. The effectiveness of either chloroquine or hydroxychloroquine against coronaviruses has not been tested in clinical trials.

As stated above under Claim 6, the U.S. Food and Drug Administration (FDA) cautioned against the use of hydroxychloroquine or chloroquine for COVID-19 outside of a hospital setting or a clinical trial due to risk of heart rhythm problems.

Claim 14:

Cahill: “In general these [corona]viruses have 30,000 nucleotides but in this [SARS-CoV-2]—there’s actually a stretch of 12 nucleotides that are not present in the other viruses, and this would not happen naturally.” [referencing Anderson et al. Nature Medicine, Figure 1]

Cahill is referencing a Nature Medicine study by Andersen et al.[10], which noted the presence of 12 nucleotides in the gene sequence for a so-called spike (S) protein, which is a protein located on the surface of the capsule that surrounds and protects SARS-CoV-2 until it locates an invadable host cell. The S protein binds to ACE2 receptors on the surface of human and animal cells, enabling the virus to enter the cells. The 12 nucleotides mentioned introduce a polybasic furin cleavage site in the protein. Scientists have found that this cleavage site is important for infection of human lung cells[11]. Other scientists have also speculated that this feature may play a role in expanding the virus’ tropism[12], that is, “the ability of a given virus to productively infect a particular cell (cellular tropism), tissue (tissue tropism) or host species (host tropism)”, as defined in this Nature Reviews Immunology article[13].

Cahill is correct that the study’s authors did not find these 12 nucleotides in the other viruses to which they compared SARS-CoV-2, namely bat coronaviruses and a pangolin coronavirus. However, the authors did not conclude that this difference could not happen naturally. In fact, they stated that other human coronaviruses also harbour these sites. This shows that there are examples of naturally occurring viruses which contain this polybasic cleavage site, and that this feature is not indicative of human engineering. Vincent Racaniello, professor of virology at Columbia University, showed in this blog post that the furin cleavage site can be observed in MERS-CoV and human coronaviruses that cause the common cold.

Cahill’s suggestion that the virus must have been manipulated in a lab directly contradicts the conclusions of the authors whose study she references: “Our analyses clearly show that SARS-CoV-2 is not a laboratory construct or a purposefully manipulated virus.”

Claim 15:

Cahill: “The PhD student from this lab [in Wuhan] died and it was at her funeral, it seems, in Wuhan that people started to get the initial symptoms [of COVID-19] after her funeral.”

There is no evidence indicating that the outbreak started at a funeral, or that someone in a lab in Wuhan, China—presumably the Wuhan Institute of Virology which studied coronaviruses and has been the center of conspiracy theories claiming that the lab created the virus—was patient zero.

The origin of the virus has not yet been confirmed, but the current most likely and scientifically supported theory is that it jumped from animals to humans and spread by human to human contact before several infections were identified at a wet market in Wuhan, China. This theory is supported by the fact that the first known case of COVID-19 had no known link to the market and neither did about one-third of later patients in the first cohort examined[14].

UPDATE (3 June 2020):
After significant concerns were raised about the integrity of a study by Mehra et al. published in the Lancet, which claimed to show that COVID-19 patients treated with hydroxychloroquine had poorer survival and were more likely to experience abnormal heart rhythms, we removed it from this review (originally discussed under Claim 6) and from the References list.



Published on: 22 May 2020 | Editor: