The purpose of this blog is to teach you about viruses and viral disease. This topic is not one that everyone understands, yet nearly everyone would like to. I was most disturbed when the Secretary of Health and Human Services, Tommy G. Thompson, referred to the anthrax bacillus as a virus. That incident crystallized in my mind the need to better educate the public about viruses.

I am your host at virology blog – Vincent Racaniello Ph.D., Professor of Microbiology & Immunology in the College of Physicians and Surgeons of Columbia University. Why am I qualified to teach you virology? I have done laboratory research on viruses since 1975, when I entered the Ph.D. program in Biomedical Sciences at Mt. Sinai School of Medicine of the City University of New York. My thesis research, in the laboratory of Dr. Peter Palese, was focussed on influenza viruses. That’s me in the black and white photo below, taken in 1977. Yes, I’ve changed.

Vincent Racaniello 1977

In 1979 I joined the laboratory of Dr. David Baltimore at Massachusetts Institute of Technology, where I did postdoctoral work on poliovirus. The moratorium on cloning full-length viral genomes had just been lifted, so I proceeded to make a DNA copy of poliovirus RNA, using the enzyme reverse transcriptase. I cloned this DNA into a bacterial plasmid and determined the nucleotide sequence of the poliovirus genome. In an exciting advance, I found that a DNA copy of poliovirus RNA is infectious when introduced into cells. This was the first demonstration of infectivity of a DNA copy of an animal RNA virus, and it permitted previously unthought of genetic manipulation of the viral genome. Today infectious DNA clones are used to study most viruses.

In 1982 I joined the faculty in the Department of Microbiology at Columbia University College of Physicians & Surgeons in New York City. There I established a laboratory to study viruses, and to train other scientists to become virologists. Over the years we have studied a variety of viruses including poliovirus, echovirus, enterovirus 70, rhinovirus, and hepatitis C virus. As principal investigator of my laboratory, I oversee the research that is carried out by Ph.D. students and postdoctoral fellows. I also teach virology to undergraduate students, as well as graduate, medical, dental, and nursing students.

Since I think about viruses every day, and I have always been interested in teaching others about viruses, this blog seemed to be an ideal forum to convey some of my knowledge on this topic.

After starting this blog, I became interested in using ‘new media’ (internet-based media) to disseminate information about viruses. I’ve summarized my use of this format in an article entitled “Social media and microbiology education“, which you can find at the open-access journal PLoS Pathogens. In addition to writing about viruses on virology blog, I also host and produce three podcasts: This Week in Virology, This Week in Parasitism, and This Week in Microbiology. I teach a virology course each spring at Columbia University, and I post videocasts of each lecture at the course website, at iTunes University, and at Coursera.

If you would like to learn about our work on viruses in more detail, please visit my website at Columbia University, or my Wikipedia page. You might also like to follow me on Twitter or Google+, where I often provide links to interesting stories about viruses. I have also written about my work on this site; links to some of these articles are provided below.

Earth’s virology course

Thirty years in my laboratory at Columbia University

Edwin D. Kilbourne, MD, 1920-2011 (his influence on my career)

Thirty years of infectious enthusiasm

Transgenic mice susceptible to poliovirus

Viruses and journalism: Poliovirus, HIV, and sperm

Poliovirus on BBC radio

Viruses and journalism: Off-the-shelf chemicals

Poliovirus is IRESistable


All of the opinions that I write on this blog are mine, and in no way represent the views of my employer, Columbia University. This information is provided for educational purposes only, and should not be considered medical advice. If you think you are sick, see your doctor. Links to other sites to not constitute endorsements of those sites.

Vincent Racaniello

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  • http://www.facebook.com/Andreita.Sanchez.Hidalgo Andreita Sánchez Hidalgo

    Dear Dr Racaniello, I have been following your classes and It have been amazing, Thank ypu for share your knowledge with us.

  • Angela

    Hi Vince…I was searching the web and came across your blog…you make this virology stuff fun to read and I think I’m a new fan :) and one that also needs some help….I’ve been doing some research on a novel Piscine Reovirus infecting farmed salmon up here in BC and they matched it to a chicken reovirus!…One of the assembled contigs with a total length of 1097bp matched the lambda A-protein (major core/inner capsid protein) of an Avian orthoreovirus (E-value 6e-71) When I googled the Evalue it took me to skyline models data base and then when I went down to the Evalue and clicked on that it took me to the novel chicken virus they matched it to…it truly was a Holy cluck moment for me when I read that it causes runting stunting syndrome in the chickens as it causes heart and muscle disease in the fish too… from most of the studies I’ve read on this, the scientists are saying PRV is equally related to both aqua and ortho genera, strongly suggesting it be made a new genus while others have decided to lump it in with that “common evolutionary origins of aqua and orthoreoviruses” I’m no expert but I don’t think a smidgen of a toenail study from 510 my ago can be compared to half chicken, half fish!..they’re claiming PRV is also acting differently in the FAST protein side of things than they thought it would, which I find rather freaky…what else has me worried is that they just put 500,000 PRV infected salmon smolts into the open net pens just up island from where I live, and while I guess our government seems to think it’s ok to grow diseased flesh for human consumption I worry if this new and improved virus could infect people?… in one of the study’s on PRV they talk about myocarditis in humans and a virus being suspected (I wonder why would they put that into a study entirely done on fish?)…when most doctors recommend to their heart patients to eat more fish and salmon do you think I have cause for concern?…has this virus jumped species….or mutated…Thanks for your time and I’m looking forward to your reply

    Angela from Quadra Island BC

  • Elham

    Dear Vincent, I am an international PhD student in one of university in Italy. I found your blog accidentally that is exactly what I needed. I have been already following your classes and It have been amazing, Thank you for share your knowledge with us

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  • JenInSF

    Vince – thanks for sharing your knowledge. I have a background in ecology and have become fascinated with viruses and infectious diseases. I no longer work in science, but I like to read (CDC Emerging Infectious Disease journal + Pro-Med updates) and learn about them – thanks for helping me get my science fix!

  • Rishat

    I am a Russian I have super immunity to influenza. I work for the best distributor of newspapers in Almetyevsk, I go around the city sell the newspaper for 15 years. A flu afraid of people who play sports in the fresh air. Not sick with diabetes mellitus other type of drink a lot of water. A flu does not like people who drink a lot of water. I propose to make a flu vaccine based on my blood. phone 79046762574

  • Yasmin

    Dear All, I am PhD student in pharmacy, currently i am reading about HCV life cycle and it is hard to me to follow and understand the virological terms – could you please clarify to me what does it mean by trans membrane domain?

    I will appreciate if you guide me to find an easy book to help me to understand this terms

  • Aiman

    Dear Vincent could you please enlighten me how to obtain bacteriophages from soil ? I am doing my Masters in Microbiology from University of Karachi . I am working on phages. I Know how to obtain phages from sewage but I need opinion of some experts how to obtain phages from soil . I can be reached at aiman.uok@hotmail.com

  • http://www.virology.ws profvrr

    I would ask Dr. Graham Hatfull – he isolates phages from soil all the time. gfh@pitt.edu

  • Emil


    I’m taking your Virology course through Coursera. I just wanted to thank you so much for everything you’re doing. I just graduated with a degree in Chemistry and unfortunately Virology never fit in my schedule. You teach in an incredibly effective manner and hold my attention the entire time you are speaking. Thanks again, keep it up.


  • Joe

    Hi Mr. Vincent,
    I am a college freshman with a interest in studying virology but do not know which path to take. I’ve been reading blogs and many people said to earn MD then Ph.D in virology while others said M.S, then Ph.D. I have a strong inclination towards getting a Masters in mircobio then Ph.D but I don’t want to end up making a mistake
    Thank You

  • Chavela

    This is my first comment. I’ve been reading on this site for hours. I answered the question, ‘are viruses dead or alive.’ I think they can sit on a shelf for billions of years–dead. They need a living source for life. I wonder, do they have any enjoyment? Coffee, sex, or just copy themselves like crazy. What is their purpose when invading a living body?
    Maybe they wanted to live off my liver–just diagnosed with Hep C 1 a. Have had 40 years from a blood transfusion of 2 pts. due to a wreck. Amazing. The blood to save my life can now take my life with all the monsters in it. I don’t where to go on this site for determining how the 3-drug treatment gives so many side effects. What is happening? How do these drugs cause so much distress? How does it interfere with dopamine production? I wish I were a biochemist–maybe my next life. With my viral load being huge, wonder what my changes are for getting rid of this. (SVR)
    I want to know also what the drugs do–what mechanism–to kill this virus. Do I even make sense? Thank you for the great discussions and analogies on viruses.
    I like it when people can intelligently discuss toss around ideas, brainstorm, being congenial, leaving their egos out in a non mean spirited way. I don’t mean to change the subject or distract. Should I be at a different place? Thank you and love your gift of brilliance from the source, whatever name you call it.

  • farouq

    Hi Dr Vincent,
    I am taking your online course Virology 1 and am excited about learning more. Are there any regular conferences I can attend in the USA? thanks
    farouq from Kuwait

  • ola

    Dear dr.vincent would you kindly tell me the difference between the N1 and the N2 numbering system in influenza viruses

  • Pankaj Upadhyay

    Hello Sir,

    My AIM and dream of my life is to find a cure for AIDS.As being a second year undergraduate student teachers didn’t help me much in research or anything but then I came across your course on coursea and its pretty amazing and easy to understand.

    You really have created a hope and hunger inside me to study more.please keep sharing because you are awesome and some day I will find a cure for AIDS , and I won’t forget to give you credit (;

    Now you are a hope for children like me who have dreams (: YOU ARE AWESOME AND I MEAN IT ( I saw your expressions in the video)

  • ASCHAE1905

    Professor Racaniello – I was taking Virology through Coursera and loved every second of it. Unfortunately, my fiance got very sick and I had to stop courses to take care of him. Do you have plans to do the course again? I only made it about halfway and would love to complete it.



  • Yong Yang

    Dear Pro. Vincent, Recently, I am screening some bioactive constituents for
    anti-RSV(respiratory syncytial virus) activity in vitro with Hep-2
    cells, the control is ribavirin, but I found the Therapeutic Index (TI)
    of ribavirin is very low, less than 10. I searched papers, it’s a big difference. So, I wonder how about the results
    in your experiments.
    Yong Yang

  • kehinde Oyeniran

    Good day to you sir! My name is Kehinde Oyeniran. I am a Master degree student in Medical Microbiology from Nigeria. Please i need your assistance concerning this virology question; ” Which of the viral diagnostic methods is most reliable (with applicable reasons)?’ I look forward to your reply.

    Thanking you!

  • Matt Dubuque

    Hi Vincent,

    I wondered what thoughts you might have on this unusual cluster of polio-like symptoms around here in beautiful, lovely Silicon Valley, said paradise rendered legendary by Nobel Literature Laureate (and our very own) John Steinbeck.


    Conversations at the CDC include whether this outbreak may be an enterovirus. Some discussion that this illness may well be underreported.

    Hope all is well,

    Matt Dubuque, San Francisco, California

  • Arjun

    Hello Pankaj my name is Arjun I am doing my 3rd year undergradute course in Microbiology.I would like to share my Ideas and informations with you.

  • http://www.quarterk.com Pankaj Upadhyay

    Sure, My Facebook Id is blessedbygodinheaven@facebook.com . You can search me there (: looking forward to talk to you (:

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  • Danny Vazquez

    Mr. Racaniello I want to Know how much time norovirus can live on top of a surface

  • Dave R.

    Hi Vincent, I just finished reading your “pathogenesis of influenza in humans” blog, which I stumbled across on the internet while recovering (slowly) from the flu and wondering why the whole recovery process was taking so long. I don’t have a science background (high school chemistry 40 years ago – seriously) but found the article quite illuminating and understandable. It was also nice to be able to chart my recovery on the graph. Congratulations on the great educational service you are providing!

  • TM

    I am a patient suffering from a “viral rash”for over two months and I am miserable. I am hoping you can shred some insight and thoughts on my condition. Here is my story. On March 18th I had a client dinner, late that evening I developed a hive like rash. I thought I was reacting to something I ingested that evening. I took Benadryl which helped relieve the itching. Over the next five days I continued to have a transient itchy red hive rash. I continued to self medicate with Bendrayl which made me very sleepy. I saw my first doctor on Monday(allergist) who informed me I had a viral rash??? I have never heard of this reaction to a viral infection. What was interesting, I never was acutely sick or febrile. I continue to this day to have a non painful swollen lymph node in my neck. I was put on antihistamine regimen which I am still on to this day. On Wednesday I developed severe malaise and fatigue and was exhausted for two days. But I never felt “sick” On Saturday I developed aching bone pain( another first). This prompted me to visit my GP the following Monday. He concurred my rash was probably viral. He suspects I was exposed to the flu. I did take the flu vaccine this year. One interesting symptom I experienced was aching at my injection site… Maybe it was in my head! During this time my work partner who I am constantly in contact with family developed the GI flu. There youngest daughter was diagnosised with fifth disease. Parvovirus. His wife as well is suffering from a rash??? I continue to have intense flare up of this transcient itchy rash. I have also seen a dermologist. All he did was provide a stronger cream to relieve the itching. I have researched fifth disease but there is not much literature on adult symptoms.. If that is what I have…
    Any suggestions or thoughts I would appreciate.

  • LKarlHya

    I‘m a Chinese.I have a question,that is there some connet between the genetic material of virus and host?

  • Fxmed

    I believe I heard you mention a virus that was found in many humans but non pathogenic. I can not find the recording. Can you tell me which virus this was? I believe you spoke abou tit at the same time you were talking about herpes virus

  • CU Student

    All of his lectures are on youtube!

  • Annette

    I am reading a portion of a textbook on immunology and in one paragraph the author states, “. . . antibodies can actually bind to a virus while it is still outside of a cell, and can keep the virus either from entering the cell or from replicating once it has entered.” In a paragraph a little further down the page, the author states, ” . . . there is a flaw in the antibody defense against viruses: once a virus gets into a cell, antibodies can’t get to it, so the virus is safe to make thousands of copies of itself.” The author seems to be saying the opposite about antibodies and viruses in these statements. Can an antibody prevent a virus from replicating once it has entered a cell? That is, does the antibody work inside the cell to prevent viral replication or does the antibody affect the virus when it is still outside of the cell so that it cannot replicate once it enters? In the first statement it seems that the author is saying that antibodies function inside a virus-infected cell to prevent virus replication. I’m confused. Thank you.

  • http://www.virology.ws profvrr

    Most humans carry anelloviruses (small ssDNA viruses0 and polyomaviruses, without pathogenic consequence.

  • http://www.virology.ws profvrr

    Antibodies to viruses can inhibit replication in several ways. Once bound to the virus particle – an interaction that occurs outside of cells – the antibodies can prevent attachment; or they can enter the cell with the virus, and prevent release of the viral nucleic acid. But if a virus particle enters cells without being bound by antibodies, it will replicate – the antibodies do not follow the virus into cells. In the extracellular fluids, not all virus particles will be bound by antibodies, so some will enter cells and be able to replicate. Does that help?

  • Annette

    Absolutely! Thank you.

  • F Gerard Lelieveld

    Hi Vincent,
    concerned member of the public here.

    In the news article Prominent Virologist Defends The Chinese Hybrid H5N1-H1N1 Research, Calls It ‘Good Science’,
    you gave the argument that:
    “Anything a scientist does to a virus in the lab is likely to cause reduced virulence, because the scientist does not know how to tinker with the virus without causing a loss of fitness.”

    Now I wonder, has your opinion changed since this research article:
    Airborne Transmission of Highly Pathogenic H7N1 Influenza Virus in Ferrets
    showed that “transmission was not associated with loss of virulence”?

    Sutton et al. used the same method as Fouchier after he concluded that artificial mutation didn’t produce him the hell in a handbasket he was looking for: serial passages of the bird flu virus between ferrets.

    When will you join the other side?
    A simple adaptation of the ferret model renders your arguments in the above news article useless. Call it the human model. I hope you delete this post, and join the other camp for a while. Hush, hush.

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  • Mansoor

    Dear Sir,
    I want to perform a TCID50 for different commercial lyophilized vaccines as a project. I can understand all the procedure but there is only one confusion. How to dilute the lyophilized vaccines to make a 1:10 dilution. I have seen a video on youtube stating that make 1:100 dilution of stock virus then dilute it 10 folds but i am not satisfied with logic. can u please help me out to about how to diluate a lyophilized virus for making a 10 fold serial dilution.

  • sachin

    Hello sir, I am very confused about, why some viruses adopt to be negative stranded RNA genome. What are the advantage over positive stranded RNA viruses.????

  • F Gerard Lelieveld

    No answer yet. Here I found the same reasoning:

  • “Dr Hood”

    I am a clinical laboratory scientist (ASCP). Although my expertise is Hematology/Hemostasis, I have long been interested in virology. During my training 40 years ago, most microbial training involved bacteria. Not much was known then about virus. It was not until the advent of HIV that I became an avid follower of viral illness and research. I am especially interested in the role of virus in cancers. As a hematologist I have learned the roles of virus in leukemia and lymphoma. Virus is suspect in breast and other cancers. Because of this interest, I own virology textbooks that associated virus as causative in cancer. The HPV group was discussed. This book is over 20 years old!!!! So my question to all of you viral experts is this; WHY DID IT TAKE SO LONG TO DEVELOP A VACCINE; WHY ARENT OTHER STRAINS OF HPV [ also oncoviruses] INCLUDED IN THE 4;WHY ISNT THERE A PLAN FOR THEM; AND WHY ARENT PUBLIC HEALTH OFFICIALS AND PHYSICIANS WARNING PARENTS AND CHI.DREN ABOUT THE DANGERS OF UNPROTECTED SEX BY TEACHING PATIENTS THAT IT IS NOT JUST ABOUT HPV.? LEUKEMIA, LYMPHOMA, BREAST CANCER, PROSTATE, ETC MAY ALL BE DUE TO VIRAL INFECTIONS!! WHY DOES THE PRESS AVOID THAT DISCUSSION AND INSTEAD PUBLISH THE JUNK SCIENCE TRYING TO ATTRIBUTE CANCER TO THE FOOD WE EAT!!!