Virus isolates, variants, strains - what are they? 

Your philosophy of free education is refreshing and welcome in a world where such noble integrity is rare. Thankyou.

I left this comment for him : "This was interesting and helpful in understanding how the terms are used in virology. What I notice at once is that the term "isolate" in virology has a different meaning than in any other venue. The sequence shown in that slide doesn't show any virus being taken out of the swab sample. The entire sample, along with the liquid it's dissolved in, is put in the lab dish with the cells. So when the cells die and beak down, how do you know that it was something in the patient sample that killed them, since you didn't do a control where everything EXCEPT the patient sample was used? And, how do you know it was a virus in the patient sample, since there are many other elements in there: human cells and mucus, bacteria, fungi, toxic substances that might have been breathed in and caught in the patient's mucus. So why is it called "isolate" when there was no point at which ONLY the virus was used?"

So question about isolates. You said you take the nasal swab, put it in a tube with some liquid, and put some of the liquid into a culture dish with some cells already growing and grow it; and that's isolation. If a person has 2 different virus, or a bacteria and a virus in their nose, how would growing them in a dish isolate them? It's my understanding isolate means to set apart from all others; or in the case of people, to quarantine or isolate someone in solitary confinement. A separation from everything else. How would this test accomplish that if the sample being put into the dish was never isolated? Bad in, bad out right? I've seen labs selling "isolated" virus, when they state the sample contains largely human and cow proteins. You also said there is no definitive definition. How is that scientific?

This was interesting and helpful in understanding how the terms are used in virology. What I notice at once is that the term "isolate" in virology has a different meaning than in any other venue. The sequence shown in that slide doesn't show any virus being taken out of the swab sample. The entire sample, along with the liquid it's dissolved in, is put in the lab dish with the cells. So when the cells die and beak down, how do you know that it was something in the patient sample that killed them, since you didn't do a control where everything EXCEPT the patient sample was used? And, how do you know it was a virus in the patient sample, since there are many other elements in there: human cells and mucus, bacteria, fungi, toxic substances that might have been breathed in and caught in the patient's mucus. So why is it called "isolate" when there was no point at which ONLY the virus was used?

Thank you so much for taking the time to share this with us!

Virologist for 40 years, it shows in your brilliant teaching style.. love your way of taking a potshot at your own profession. Brill

Wow, as someone who was not trained to understand I can tell you that I understood perfectly. Fantastic.

Thank you for clearing up these terms, which are vital to understanding the subject.

Like other commentators who are not medically trained my first stop moment was what about the virus being isolated from the propagating solution. How does that work?

24:39 ''Media scares you that is how they get your attention'' ----and how they control you.

But how do you isolate the "sample" from the snot? You did not mention centrifuging. Is that not necessary? Isn't the snot full of all kinds of stuff?

Can you give an example of someone taking a virus from on organism and making another organism sick from it?

The book Virus Mania is contrary to many ideas presented here. I would love to hear your side and defend virology against a book like Virus Mania. Thank you so much for your efforts!

How do you know that what you are growing on the medium is the virus you are looking for? In the sample from the nose are surely millions of different microorganisms, so how do you know which one causes the symptoms? Don't you need a control sample to make sure that a "healthy" nose doesn't provide the same virus?

Tnx for this. Any chance to explain PURIFICATION? And whether it was done ANYWHERE?

I watched your Virology Course in 2019. I then found myself glued to our winter 2020 courses. I so appreciate your dedication to teaching in terminology that is accessible to me a 45 year old plumber. While I research for fun all sorts of topics this last year has been less about random thoughts of history and science and far more about the medical situation we have found ourselves all effected some to their very foundations of life. I use your weekly shows and your past courses as reference points when evaluating new information or looking at past findings. This is because I truly believe your work is about the knowledge and not at all about politics and / or money. I've seen you bring up something you were mistaken on and stand firm in the media 'scariant' before details. That's integrity over profits. Thank you

Thank you Vincent. Thank for using science to bring clarity in these disturbing times.

Brilliant, Vincent, as ever. Thank you so much for your limitless dedication to public education of virology.

I would love to undersand the topic of 'isolating a virus'. At 3:16 you explain the sequence of the creation of the isolate. It seems to me that all kinds of stuff is grown in the petri dish (step 3). I fail to see how the growth in the petri dish can be referred to as something that is isolated from something else... What am I missing?

The term "Isolates" should not be used. Some call this genetic material Tags. Tags are found in different species, they are not unique. These Tags are extended and placed into a computer which fills in gaps and produces an "In-Silico" genome aka a "made up" genome which can be labeled whatever you want. Viruses are not alive nor have they ever been isolated.

Okay, so you never purified it and thus NEVER truly isolated it !

Love all your passion been following you since 2017.. Please keep up the good work

Thanks, Vincent. You're doing a huge service combating the miasma of confusion and ignorance. More of these smaller spoonfuls of teaching, please.

what i like about professor vincent is his technical and elegant terminology

Very cool, Vincent! Thank you for all your efforts.

where is the cov2 isolate in a court of law ey?

Dear Professor Racaniello, thank you for investing time in so eloquently educating non-scientist in the language of your expertise. I believe the survival of human kind, perhaps our planet, will pivot on the collective elevation of scientific "literacy." Your ability to translate complex concepts into digestible explanations for the uninitiated is a significant gift to us all. Deep respect and admiration - Teri Ashley

Variants, isolate, strain. Viruses suffering from an identity crisis

Thanks, Vincent. That was so clear and presented so calmly and professionally. Just great. Is that TWIV 3 1/2 for this week, haha?

Bravo Vincent!!! ❤️ I hope you know you are loved and appreciated by many. Keep up the good work and stay safe. BTW, I just read a "fun" novella by Jack London, "The Scarlet Plague" 😱 What a scary, sobering tale. It almost makes one feel better that WE didn't get it so bad. The most sad thing really is not the virus... it's "us"...😭😭😭

If you say Covid19 three times....yep you tested+

Great lecture Dr Vincent! Thank you very much!

Thank you Professor. A gem of a video. Hope the P1 stays in the variant category!

What is the fluid in the tube?

Thumbs up! This is very helpful. Thank you. I'm not a med student. My field is more mathematics and engineering. But my main study is intelligence, epistemology, logic. The study cells, genetics, viruses, building blocks of biology has been a major past time of mine for the past few years. This channel has been of amazing benefit to me. I honestly, am apprehensive about the word "virus" as terminology. Because of what it implies. Because I could easily consider exosomes to be the same thing. But with no harmful connotation attached to it. The problem I'm having with this channel is not finding any sort of information on the validity of sarscov2. As a strain, and its incubation properties that supposedly make it more dangerous. As far any evidence I've seen. All illnesses in the past year have been no different than any standard flu, corona, rhino, etc. I have seen absolutely zero indication anywhere that proves there is anything new or more dangerous that news is embedding into the population. Thereby, contributing to their fears and susceptibility to illness. And this applies to government officials and WHO as well. As I understand it, over the past decade, WHO has significantly diminished their criteria for declaring a pandemic. Therefore, this supposed 'pandemic threat' would have never been mentioned or heard of, according to WHO's prior criteria. Then there's the testing. As far as I understand it, the primer enzymes used for replication of corona, have no bearing on the strain of corona. So it seems that tests can only determine presence of corona. Not strain. I was a bit disturbed watching TWV last year in the early stages of this upcoming threat because of somebody saying this is the real thing, it's actually happening, etc. What? No information on experimentation to actually determine if it's a real thing by anybody in that podcast. And just randomly saying it's the real thing based on what exactly? I haven't watched every single video on this channel. So maybe there is something I missed. But my question is about evidence of the existence of this sarscov2 strain, and evidence that it's actually in any way more dangerous than common corona viruses. What exactly is the science that this is indeed a real variant of corona. And if it is a variant, what evidence is there regarding the claims about this variant being significant enough to be a strain, and more dangerous. Likewise, how are these tests even determining strain if the basic primer for replication of corona doesn't differ for any variant? Thank you.

Vincent! You Rock! Thanks for all you and your talented colleagues do for us! Cheers from Minnesota

Questions: 1) are there any actual isolates of “the virus”? 2) if not, why? 3) if not, does it matter in terms of developing treatments, vaccines, etc.?

great but isn't the gaping hole that the variants are derived by highly speculative software processing of material which contains many unknown organisms?

You don’t mention purification

The Truth About Virus Isolation 🤫 Dr. Sam Bailey

I thought virology was a science, not a humanities subject.

Thank you. Wrt what's happening at 5:00 I got lost. Is each one of these genome sequences taken from an isolate from a defferent subject? Or are there different isolates from one subject? Or can many different sequences be taken from one isoate. If it's the latter, how can the same isoate provide different sequences?

From the UK my thanks to Vincent & his colleagues for some very useful and informative sessions. I wish we had someone over here doing the same thing. Perhaps then we wouldn't have the hysteria and chaos induced by our media and government.

Wow missed this back in the day. Your 2024 virology class, im half way through is awesome. Hard study though without the $200 textbooks.. ouch!

Your videos have taught me a lot. Thanks!

Hopefully we can get core members of the media to hear and understand this message. I have little hope of that, but simply had to say it. Time to find people to share this with.

Thank you Sir..for this great lecture..like you always do. Big fan of your book.

Also, Can you talk about the sea slug that ate the algae and got it's DNA and became a photosynthesizing slug....

Thanks for these definitions. I wish the doctor would tell me the name of the serotype I got this time around every time I get diagnosed with dengue. The last time, January 2021, I was diagnosed with dengue for the third time since 2008, not sure if it was false because I then also tested positive for SARS-CoV-2 in an antigen swab test after testing negative in SARS-CoV-2 serology test. I want my virus infection badges of honour to reflect the most accurate description available. Second time I got dengue (2012) the first doctor I went to for a diagnosis (in Indonesia) said it was just a "typical virus" and did not want to bother examining my fever profile or do a serology test. Am wondering how many virus pass through communities like this "undiagnosed" before finally infecting someone who has access to a professional doctor.

This is helpful and interesting. I hope you will have a lecture on genotypes, subtypes, isotypes, clades and biotypes as well.

looking forward to hearing your thoughts on the current variants!

Excellent and much needed education. Thanks a lot!

Excellent ! CNN and MSNBC talking heads should be required to study this presentation.

Hi Vincent - another great video thanks. I got a bit confused when you started to talk about clades. What is the difference between a clade and a variant?

Very valuable video. I wish some people take a time to watch this video. Your method of teaching is unique because you are able to explain a very complicated subject in an easy way to understand. Thank you

Ii isolate pure viruses ? If You don't mind Thanks

I wish he had been advising government and media for the past year instead of the sensation seeking incompetent fools we’ve had.

Excellent ! Nextstrain is a website I've been showing people for a while now, but methinks it's a bit too technical for the average layperson. Question: Do you think it's possible that SARS-cov2 is related to PRRS virus ?

Thank you so much sir for this Wonderful informative session you are the best virology professor in World 👍👍

Hello, first time here. Question: Have we isolated Covid-19 using the original koch's postulates or the modified Koch’s postulate?

Where is the follow up to this? Would like more info on whether or not these variants are as scary as portrayed

Is there a Claude an nature from which the first Wuhan “isolate” or more properly gene sequence arose? That is do the insertions such as the polybasic furin cleavage site demonstrate ancestry or does this point to a lab manufactured pathogen?

we want vincent to play his guitar in a TWIV sing along!!!

Thank you for the explanation, viruses are so cool!

Thanks for that. Very helpful. How would you define a lineage in this group of terms presented here? Silvano Wendel, from Brazil

the big question - which is not made clear in this video is. does a variant derive from a physical isolate and compared to another physical variant or does it come from a genom sequence? thank you for the sit down vid.

Thank you Dr. Vincent, for taking the time to teach so much in an accessible language.

Dr. Vincent, can a reverse transcriptase from a retrovirus capture a mRNA from another virus species and assemble then a correspondent DNA sequence that could be integrated into cell DNA if a viral integrase is active in an infected cell?

Very Informative eased my worry a little bit, thank you.

Thank you for sharing this information. James

Hopefully some news outlets can learn something from this video.

The problem, is that when it comes to selling newspapers or advertising space on social media, the correct term and usage doesn't matter one jot. Bending the truth and changing facts are part of the game. Education is one thing, profit is something else.

fantastic job! I hear you talk about fitness, founder virus. Maybe some clarity?

I love you so much Mr Vincent.

Even though he supports the mainstream narrative, I like to listen to him (although not much). Clearly a man who is very passionate about viruses and can explain things clearly (in the limits of official virology). But unfortunately, because no one is asking in that moment, he doesn't explain why the "isolate" is not an isolate in a direct sense. Okay, he explains that viruses are grown in a cell culture (implying that they can't be isolated in any other way), but then he admits that even this kind of isolation is skipped most of the times and genome sequencing is done instead. But he doesn't explain how do you separate the genetic material from all other sources that come from a human body - how can you call this the genome of a virus. Would be so great to have someone on the other side to ask questions and debate with him.

Thank you for explaining. I recently had to try to calm someone down over the new variant news, because he said it was the end of the world. Variant turned scariant by news.

Almost every one of those genomes are nearly unique. I’m sitting in front of the whole database as I write this and can confirm the professor. The idea of a strain is meaningless. The quasispecies is real.

Thank you Vincent for an excellent video explaining strains and isolates! You are provide a great service to the world with your outstanding educational podcasts and videos.

Thanks a lot professor!! All your videos make me get used to molecular biology easily!

Thank you for trying to bring clarity to terms that are often interchanged in the press and even in the scientific literature. Really appreciate that. Two questions: (1) re: an isolate, does the definition need to be limited to a species of virus rather an any virus? Otherwise, how would one have an isolate of, say, SARS-CoV-2? Of course, this would require defining a species . . . . (2) re: a clade, it appears from what you said and showed in the diagram that a clade is a virus ancestor and ALL its descendants. Is that correct or did I misunderstand? Again, thank you for your many videos and time dedicated to education!

Thank you. That was very helpfu.

when a genome is obtained for an isolate, is the genome take or "measured" multiple times to get statistical dominant genome?

You mention that "aminoacid mutation" is wrong. However, a missense mutation is a mistake in the DNA which results in the wrong amino acid being incorporated into a protein because of change, that single DNA sequence change, results in a different amino acid codon which the ribosome recognizes. Changes in amino acid can be very important in the function of a protein.

Excellent explanation. TY

Great thanks Dr. Vincent Racaniello

And what if it's a gain of function experiment......all bets are off people

What about the Andromeda Strain?

So what happened to the purification step? You isolated some mucous that is full of who knows what and called it a virus.

Hello Vincent. It would be interesting to hear your thoughts also - in a future video - as well as whether the variants are a cause for concern, whether the attention the virus has received and our reaction to it has been warranted (e.g. mass lockdowns that have gone on for months in places). Or whether you think it has been exaggerated (i.e. the fatality rate has been too low to warrant the reaction) and maybe who do you think should be given a vaccine? (0 - 100? 50-100? 65+ vulnerable people etc)

Great info! Much appreciated!!! A bit off-topic but I have never heard the word nomenclature pronounced the way you do. Maybe it is just a regional thing but it caught my ear :) Not that I'm an expert in any way.

Nice strat.

So, do viral variants differ in their genotypes from an ancestor on a specific single clade?

Hi Vincent. I really enjoy your videos and podcasts. I have a question for you. Is it possible that you can explain how is the efficiency of a vaccine calculated? There are many videos circulating in Mexico that create a lot of doubt on wether to apply the vaccine or not due to this topic. Please enlighten us and help us change this fear in our people to get the vaccine.

So, does that mean that any true new strain has to also be a new serotype? Does that work in reverse - are all new serotypes also new strains? Same for genotype and variants - they seem to be two words that describe the same thing. Did I get it correctly? Edit: in both cases the distinction seems to be only the method through which the new virus was described, not any physical difference in the virus itself.

Over time how long did it take to mutate and then to find the 3 distinct different polio strains? And why did the strains 2 and 3 disappear in humans? We’re they weaker than strain 1? What makes a strain more virulent?

My question is..How much of a concern are these so called "variants" of Covid-19? My other question is.."Can mass vaccination resullt in more virulant mutations or "strains"?

Qestions is isolates are pure viruses?

Thank you, Dr. Vincent! Lots'a love, cheers, & Mabuhay, from tropical Philippines!

Thanks Vincent!

Well it should be isolated and then compared and study reproduced. Just like my genome sequence is not me the genome sequence of the virus is not the virus