There has been
Studies that successfully isolated the virus from the sick human
January 2020 [1]
Peng Zhou and colleagues from the Wuhan Institute of Virology grew a novel coronavirus (later to be called SARS-CoV-2) in cell culture (isolated) from bronchoalveolar lavage fluid collected from an ill and RT-PCR-positive female patient (ICU-06 in Spike tree=WIV04/2019 virus). The patient developed no IgM antibodies for Legionella pneumophilia, Mycoplasma pneumoniae, Chlamydia pneumoniae, respiratory syncytial virus, adenovirus, Rickettsia, influenza A virus, influenza B virus and parainfluenza virus.[1]
The virus was called nCoV-2019 BetaCoV/Wuhan/WIV04/2019 and grew in Vero E6 (grivet, or African green monkey kidney cell line which lack genes to encode type I interferon, so they mount a defective antiviral response) and Huh-7 (human adult liver cancer-derived cell line) cells. Virus-induced cellular changes (cytopathic effect or CPE) were observed.
Whole-genome sequencing (WGS) was used to identify the unique genetic sequence of the cultured virus and a specific real-time reverse transcription-polymerase chain reaction (RT-rPCR) designed to allow screening of more sensitive and rapid screening of more samples. The RT-rPCR was tested against human endemic CoVs (229E, OC43, HKU1) as well as MERS-CoV, SARS-CoV and others, and was found to be highly specific for SARS-CoV-2.
The authors also saw viral particles. Electron microscopy (EM) was used to visualise virus in cultured Vero E6 cells after they had been inoculated with the patent sample.
They also showed that the antibodies from five infected people could neutralise (=prevent) infection of Vero E6 after incubated dilutions of patient sera with a cultured virus preparation and added to cultures of uninfected cells. An antibody made in horses against the original SARS-CoV could also neutralise the virus however serum from two healthy people in Wuhan could not.
February 2020 [2]
Jeong-Min Kim and colleagues from South Korea inoculated RT-rPCR-positive patient nasopharyngeal and oropharyngeal samples onto Vero cells. After most inoculated (but not mock-inoculated) cells were showing CPE, they were harvested and tested using the two RT-rPCRs (Corman et al. RdRp and E; these detect viruses in the genus Sarbecovirus). RT-rPCR testing found an increase in viral RNA which the team estimated at 10-70-fold.
The study also examined three-day post-inoculation cells using EM. They found virus-like particles in vesicles within the infected cells.
To confirm that the virus was indeed SARS-CoV-2, the authors conducted WGS, naming the SARS-CoV-2 variant they’d isolated, BetaCoV/Korea/KCDC03/2020
February 2020 [4]
This is a method for culturing SARS-CoV-2 from patients samples. It doesn’t delve into virus characterisation though. Nonetheless, the image below shows CPE on a monolayer (=single cell layer) of African green monkey kidney Vero C1008, clone E6 cells (ATCC®-CRL-1586).
The CPE was confirmed as being due to SARS-CoV-2 by RT-PCR and sequencing.
March 2020 [3]
Leon Caly and a crew from Australia isolated the virus from an ill traveller from Wuhan. The virus was detected using an in-house (designed by this team) RT-rPCR. The nasopharyngeal swab was used to inoculate the Vero/SLAM cell line.
Growth was seen both by the CPE induced and the use of that specific RT-rPCR to show an increase in the presence of SARS-CoV-2 RNA (decrease in CT)
Cell-free liquid from infected cultures (called supernatant) and cells from the cultures were each examined using EM, finding particles with characteristic coronavirus morphology (=shape) and the same particles inside vesicles within the cells.
To further characterise the amplified agent, WGS identified the genome and names this virus BetaCoV/Australia/VIC/01/2020.
August 2020 [13]
Steffen Klein and colleagues used the SARS-CoV-2 variant called BavPat1/2020 to grow in VeroE6, HEK293T (human embryonic kidney cell line expressing the SV40 T antigen), Calu3 (from adult lung adenocarcinoma) and A549 (from human adult lung carcinoma) cells – some made to express the SARS-CoV-2 receptor molecule (ACE2). They knew that what they were seeing below was SARS-CoV-2 because they infected these cells with a known and well-characterised SARS-CoV-2 virus.[13]
Single virus particles and the structures on them could be seen using cryo-electron tomography. Virus particles can be seen caught in the act of budding out off infected cells and
The authors could even measure the distance between spike protein trimers (a spike ‘protein’ is
October 2020 [6]
Beata Turoňová and
Some of this stock was later thawed and used to infect a fresh new flask of Vero E6 cells. After six hours the cultures were fixed (treated with a chemical to kill the cells and inactivate the virus while retaining the cell and virus structures – like freezing them in time). This preparation was clarified twice by centrifugation (now a pretty pure preparation of virus + salty solution). This was then layered gently onto a cushion of sucrose (20% weight per volume) in a special tube. The tubes were centrifuged at very high speed (30,000 rpm) in an ultracentrifuge and the pellet – consisting of virus (any less dense material like small particles of cell debris couldn’t travel through the more dense sucrose cushion) – was suspended in a tenth of a millilitre of saline.
They now had a very pure preparation. There are no Vero E6 cells or bacteria or broken up pieces left, just the tiny virus particles.[16]
This was then prepared for cryo-electron tomography studies which allowed the investigators to view and produces images of single virions and even individual projecting spike protein trimers.
Some amazing detail can be seen below. A preparation of a virus can’t get much more “purified” than this.
NOTE ON ANTIBODY CROSS-REACTIONS: You can see here and elsewhere that there are cross-reactivities among commercial antibodies which allow them to be used to detect SARS-CoV-2. This isn’t a problem for general diagnostics though, because SARS-CoV (or any bat-related SARS virus) isn’t circulating in humans anywhere anymore. Also, we know that the SARS-CoV-2 detections we make using RT-PCR aren’t from a different virus because of all the genetic sequencing that’s been done to show it is SARS-CoV-2 that’s present in sick COVID-19 patients.
Evidence of SARS-CoV-2 isolation and visualisation in other ways
Below is a brief list of some major feel-good SARS-CoV-2 discovery announcements that came to us through the mainstream media or University websites.
- Melbourne scientists first to grow and share novel coronavirus
https://about.unimelb.edu.au/newsroom/news/2020/january/melbourne-scientists-first-to-grow-and-share-novel-coronavirus - China coronavirus: Hong Kong researchers have already developed vaccine but need time to test it, expert reveals
https://www.scmp.com/news/hong-kong/health-environment/article/3047956/china-coronavirus-hong-kong-researchers-have - China CDC developing novel coronavirus vaccine
http://www.xinhuanet.com/english/2020-01/26/c_138734908.htm - Coronavirus: Scientists isolate virus responsible for deadly Covid-19 outbreak
https://www.independent.co.uk/news/science/coronavirus-covid-19-virus-isolate-canada-scientists-mutations-strains-a9399226.html - I study viruses: How our team isolated the new coronavirus to fight the global pandemic
https://theconversation.com/i-study-viruses-how-our-team-isolated-the-new-coronavirus-to-fight-the-global-pandemic-133675
Free-to-use images of the SARS-CoV-2 virus
These images are made public by the US Centers for Disease Control ND prevention via their Public Health Image Library (PHIL). A fantastic resource for virus images. The exact details of how the viruses were prepared aren’t present, nor the ways in which SARS-CoV-2 was confirmed. that may be a problem for you. However, I’m sure they were prepared and confirmed using the exact same methods as those listed above.
Postulating into failure
Koch’s postulates – derived from his work on bacteria – were formally proposed at a lecture by Koch in 1890.
For context, that’s before we had ever visualised a human or plant virus, before organ or cell culture of viruses, before sequencing ofo viral genes or genomes and before we had labelled antibodies we could as probing tools to show viral proteins in tissues. It was known that this toxic stuff (virus, from Latin, translates to ‘slimy liquid, poison’) was smaller than bacteria because it passed through filters that stopped them, and yet could still cause disease. Discovery of human viruses came later still (Yellow fever virus, 1901-1921).
Koch’s postulates were never intended to be rigidly applied, even then. In fact, trying to strictly adhere to them probably delayed the discovery of viruses.[11]
So let’s move away from the 1890s…this revision by Fredericks and Relman (from Fenner and White’s Medical Virology (Fifth Edition) is more much more relevant to recent decades.
How do we know the SARS-CoV-2 in these earlier studies wasn’t the flu or something else that made the patients sick?
Fair enough question. Let’s look at one variant of SARS-CoV-02 because it mentioned a couple of times in the studies above. BetaCoV/Germany/BavPat1/2020 p.1 has been made available for researchers via reliable and professional providers of such biological materials (linked above). It was collected January 28th from a hospitalized male patient from Munich who was described as the index case of the Bavaria cluster in Germany.[14] He was initially suffering from cough, fever and diarrhoea. The SARS-CoV-2 variant from this patient is listed on the sequence database, GISAID, as hCoV-19/Germany/BY-ChVir-929/2020 (with it’s unique identified EPI_ISL_406862). It was sequenced from the original sample, not undergoing any cell culturing first. Obviously, after this, the virus was cultured and made available as a resource for other scientists to use – which it clearly has been and put to very good use.
SARS-CoV-2 was confirmed in all of these cases by careful testing at two different laboratories. All patients in this Munich-based cluster [14] were also tested for all other important respiratory viruses using sensitive PCR-based tests. These included:
- HCoV-HKU1
- HCoV-OC43
- HCoV-NL63
- HCoV-229E
- influenza virus A
- influenza virus B
- rhinoviruses
- enteroviruses
- respiratory syncytial virus
- human parainfluenza viruses 1, 2, 3 and 4
- human metapneumovirus
- adenoviruses
- human bocavirus
No concurrent infections were identified. The initial case in the cluster, who provided the sputum that was sequenced, also seroconverted at day 10 after symptom onset showing the body’s immune response o the viral invader. He was still shedding RT-PCR detectable viral RNA in the sputum and stool, but not nasal swabs, 21 days after onset.[14]
All of this sums up as: the studies done on this virus are studies of this virus. These were not accidentally studies of some other (completely unknown beforehand by the way) virus. And the sequence was not “tainted” by culturing; the SARS-CoV-2 entire genetic makeup was determined from material taken directly from the patient who was sick due to this virus and not another virus, at the time. They were also sick with an acute respiratory illness traditionally typical of a viral cause. It’s a tight case.
Do we know if SARS-CoV-2 causes disease though?
Well, yeah. I mean, if we overlook the many cases of COVID-19 patients harbouring SARS-CoV-2 and no other virus and if we willfully ignore for a moment the strong links with COVID-19 signs, symptoms and progress and virus presence and replication kinetics, there are also animal studies showing that introducing this pathogen, causes disease.
One good example,[7] because it reproduces some of the
Another primate study [8] administered SARS-CoV-2 via the nose and throat to Macaca fascicularis (did not use a virus-free control group). Only one monkey developed symptoms (cold-like) and all developed antibodies to a region of the spike protein and
So why do some think SARS-CoV-2 isn’t real or hasn’t been properly “purified”?
I don’t
Some of the concern could come from papers like this one [12] which notes that researchers need to be careful when growing a virus in culture because the process can result in genetic changes or mutation. Very true. Cell culture cells often originate from an animal that is different to the one in which the virus originated so there can be pressure on the virus to produce mutant variants which are better adapted to the new cellular environment. But today we can sequence the new virus’s entire genome – the code for all it is and can be – before (or in parallel or after if we dip into the original samples several times) we try and culture the virus. That way we have our “baseline” genetic code against which we can compare the cell culture code. Indeed scientists like to do this to see how the virus is changing and explain why new behaviours in culture may occur.
The earliest virus discoveries were made simply by noting that the thing causing disease could not be filtered out of a liquid using a very fine porcelain (Chamberland) filter, the way bacteria could be. Basic stuff but the foundation of virology.[9]
The disease could be passed along by injecting fluids or ground-up tissues from an infected plant or animal into a new plant or animal and watching disease develop. All very crude yet accepted at the time as evidence for a “virus” being present even if that couldn’t be characterised at the time. As we can see in the Table below, acceptance has changed with technology alongside the flexible careful thinking of experts in the field. To be clear, that expertise is not in play among those who refuse to believe SARS-CoV-2 is a real virus.
Those “filterable agents” were in preparations that were no more “purified” than a virus preparation obtained from a cell culture supernatant today, and yet they were enough to create the field of virology.
Since then we’ve been able to add many new tools to the characterisation process – visualising individual virions and their
There is – as you can see for yourself here I hope – an embarrassment of rich evidence for the existence of SARS-CoV-2 and its links to COVID-19.
Some final thoughts
I know there will be comments below (I’ll make sure to publish some of the less offensive ones 😉) to the extent that ‘I don’t care what y’all say, I ain’t seen no evidence, make it empirical, abide by the Koch’…or something.
And that’s all well and good.
There is evidence and some of the most significant parts of it are listed above.
It convinces me. If it doesn’t convince you, there is nothing more I can do except ask what it would take to convince you and in the meantime assure you that you are wrong on this one. Yes, the ‘COVID virus’ is real.
References
- Discovery of a novel coronavirus associated with the recent pneumonia outbreak in humans and its potential bat origin
https://www.biorxiv.org/content/10.1101/2020.01.22.914952v2 and then
https://www.nature.com/articles/s41586-020-2012-7 - Identification of Coronavirus Isolated from a Patient in Korea with COVID-19
https://ophrp.org/journal/view.php?doi=10.24171/j.phrp.2020.11.1.02 - Isolation and rapid sharing of the 2019 novel coronavirus (SARS‐CoV‐2) from the first patient diagnosed with COVID‐19 in Australia
https://www.mja.com.au/journal/2020/212/10/isolation-and-rapid-sharing-2019-novel-coronavirus-sars-cov-2-first-patient - Culture of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; f.2019-nCoV)
https://www.protocols.io/view/culture-of-the-severe-acute-respiratory-syndrome-c-bcduis6w?step=5 - Causation and Disease: The Henle-Koch Postulates Revisited
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2595276/ - In situ structural analysis of SARS-CoV-2 spike reveals flexibility mediated by three hinges
https://www.biorxiv.org/content/10.1101/2020.06.26.173476v2 & https://science.sciencemag.org/content/370/6513/203 - Comparison of nonhuman primates identified the suitable model for COVID-19
https://www.nature.com/articles/s41392-020-00269-6 - Comparative pathogenesis of COVID-19, MERS, and SARS in a nonhuman primate model
https://science.sciencemag.org/content/368/6494/1012.abstract - CONTRIBUTIONS TO THE PATHOLOGY OF EXPERIMENTAL VIRUS ENCEPHALITIS. I. AN EXOTIC STRAIN OF ENCEPHALITOGENIC VIRUS
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2130936/ - Human viruses: discovery and emergence
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427559/ - Virology: From Contagium Fluidum to Virome
Enquist LW and Racaniello VR, Chapter 1, Fields Virology, 6th Edition, Volume I. Editors Knipe and Howley. - Amending Koch’s postulates for viral disease: When “growth in pure culture” leads to a loss of virulence
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5182102/ - SARS-CoV-2 structure and replication characterized by in situ cryo-electron tomography
https://www.biorxiv.org/content/10.1101/2020.06.23.167064v2 - Virological assessment of hospitalized patients with COVID-2019
https://www.nature.com/articles/s41586-020-2196-x
Views: 10772
Great summary of this issue. I have been in discussions with people who insist SARS-CoV-2 has not been isolated properly, they keep mentioning Koch’s Postulates, especially the part:
“The microorganism must be isolated from a diseased organism and grown in pure culture.”
Even though this is clearly impossible for a virus…
But this has been done. Multiple times. See https://virologydownunder.com/sigh-yes-the-covid-virus-is-real/
Hi Ian,
Thanks so much for all the great information!
We’d like to feature your ‘Swiss Cheese’ graphic (from Twitter//Oct 15th) in our next newsletter if thats ok? We’re writing recommendations for parents travelling with multiples (twins/triplets) this Holiday season.
Happy to send you the newsletter draft if you’d like.
All the best,
Mary
Happy for you to use the image with attribution – the latest version is on here https://figshare.com/articles/figure/The_Swiss_Cheese_Respiratory_Virus_Defence/13082618
Thank you! I’ll be including links to your website and twitter pages with it (draft below).
Much appreciated – you rock!
“Wherever you go, and however you travel, the rules are still the same* – and in combination, they are the best way to layer up your defenses. The “Swiss Cheese Analogy” (nicely laid out below by – Ian Mackay, PhD @MackayIM) is a simple and effective way of explaining this to your family: (pic)”
Thanks, good piece except for the ‘sigh’ at the beginning.
Sorry but that’s the benefit (to me) of this being my personal blog. I can be human. And having to battle to make this point is more than exasperating.
What about Exosomes ?
What about them? You provide me some evidence that SARS-CoV-2 are actually exosomes and virus has not been isolated.
I don’t know what Seth means by “What about exosomes?” but my question is, why can’t viruses be isolated and purified for study by the same methods that exosomes are isolated and purified?
Ian – this is a fantastic article, and places much more confidence in the work to understand this virus than I have been lead to believe. I’ve been on the fence as to whether there has been sufficiently robust work to clearly identify and isolate the virus, sequence it knowing it is both the culprit and free of other genetic material, and then prove its pathogenicity in humans and robustly show the linkage to COVID-19. In part, this caution has come from what seems to be an obsession with just one tiny part of the virus for PCR testing and vaccine development (the ORF1 Spike Protein), and in part due to what seems to be solid investigative work here that throws serious doubt to the genetic sequencing and isolation/pathogenicity work.
https://in-this-together.com/covid-19-evidence-of-global-fraud/
I am clearly not a virologist or microbiologist, and I this seems to be the problem leading to mass caution. The science and language is so black box to everyday (intelligent) folk, that it’s hard to decipher both the evidence and the debunking.
I wonder if you could comment on the article above, demonstrating where the author has misunderstood or manipulated the science? This would help in closing the scepticism down, beyond true great work above.
Thanks, Steve
PCR tests are not targeting Spike. No, I won’t be commenting.
Dr MacKay, I took you up on your offer of sharing your Swiss cheese infographic with attribution. Here is the link to my post: https://www.linkedin.com/posts/thomas-t-h-kern-b155485_pharma-covid-swisscheesemodel-activity-6742066669792870400-yAU4
Thank you for helping to educate our benighted world
To actually demonstrate the existence of the COVID-19 virus two steps would be necessary:
1. Isolation of the virus, e.g. produce a sample that only contains prospective COVID-19 virions and nothing else – no material from the host cells, no bacteria, no other viruses and no Extracellular Vesicles
2. Sequencing of the genome of these isolated virions
None of the studies quoted in this blog post fulfills these criteria. The closest is [6] where actually something was isolated, but since there was no step 2 – sequencing of the genome – there is no proof that this was really the hypothetical COVID-19 virus. Reminder: The COVID-19 genome so far has only been “reconstructed” at the computer based on a few fragments of RNA of unknown origin floating around in a cell soup.
1. That is not at all required except by non-experts seeking to create their own demands. But purified virion preparations have been created as described in this blog.
2. Sequencing has been completed from >5,782,000 viruses. Your premise is that these are all incorrect if not from a super-pure preparation and that all the experts who do this work and understand the process, are also misled or misleading you? You are very wrong and clearly don’t have a good understanding of the science here. Perhaps best you read up on it a little more?