Richard writes:

the fu ‘humor’ is tasteless and more apropro 4 bevis-butthead mentality, not role model type academics, love the show

Jakob writes:

Dear Twiv team

I am a huge fan of your podcasts. I realize that a lot of time and energy goes in to continuously producing them with such high quality and I think that it is truly outstanding that you do this for us free of charge.

I have a comment regarding Alan´s influenza vaccine efficacy pick that shows 71.4 % vaccine efficacy in preventing hospitalizations. The idea of getting at influenza vaccine efficacy by just screening people who are admitted to the hospital with a suspected respiratory infection is in my view somewhat problematic. The idea is that cases and controls will be better matched in terms of risk of disease (acute respiratory hospitalization in this study) and propensity to seek or require care. This should in theory reduce some of the confounding by factors associated with vaccination. This reasoning requires that risk factors for developing a large variety of both viral and bacterial respiratory infections in a wide age span (18 years and above) are the same. It also requires that the propensity to seek care is similar regardless of diagnosis. To put this in other words: If a patient vaccinated against influenza is admitted to the hospital because of pneumococcal pneumonia it is hypothesized that he would have sought care if he had acquired influenza and the fact that he got pneumococcal pneumonia and not influenza is attributed solely to vaccine effect.

In my view a bigger problem with the CID article than the selection of cases and controls is the small sample size. They managed to enroll 169 eligible participants and only 17 had influenza. To draw any conclusions on vaccine efficacy on such a small material seems shaky.

I believe that the study by Baxter et al. (link below) is a much more robust way of getting at influenza vaccine efficacy in preventing hospitalizations. This methodology has its own problems but is in my view superior to Alan´s pick.

Someone (Nick) probably has a more intelligent take on this and I would be delighted to hear what you guys think.

Thanks again for a great pod.

Kind regards

Jakob Nilsson MD,PhD

Division of infectious diseases

Karolinska University Hospital

Stockholm Sweden

Nick writes:

1. Previous paper from the same group, with a somewhat different outcome:

2. It’s similar to their earlier study we included in our meta-analysis. not as clear method wise this time, typically its ok design; i don’t understand how they got significance over 65 with such few numbers; also with their previous paper none of the 3 years was significant on their own, but with less flu it was significant this time; just don’t forget its not a fair comparison to compare this study to recent VE studies in the MMWR, different outcomes.

3. Paper on the test-negative design:

Justin writes:

Salutations TWIV team!

I have been meaning to write this since I listened to TWIV 223 on Monday, but life occasionally gets in the way of my TWIV schedule. I really enjoyed the EEEV discussion and thoroughly enjoyed the episode title and the viral discussion in snakes. While listening you referred to the venomous snakes as poisonous. The two terms may seem interchangeable, but for me I twitch to the level of someone saying they have the stomach flu. In a poisonous animal the toxic compound is injected or absorbed, like a poison dart frog. Whereas, a venomous organism uses a special adaption to deliver the toxic compound through a stinger or fangs etc. Thank you all for the wonderful podcasts,


@drricky writes:


“This is the basal tree for the evolution of all eukaryotes (taken from Everything labeled with an arrow, and also everything in the box, fall into the category of protozoa. Sometimes protists. This illustrates why the terms are actually morphological descriptors, and not evolutionary ones. This diversity, of course, only became apparent in the age of molecular phylogenetics. Even so, the genomic samplings are heavily skewed to a small corner of this tree.:


The crew on #TWiV are better experts than I, but I think the only real distinction based on sequence between retroviruses and retrotransposons is that the latter have lost the env genes that enable them to transpose out of the cell. In fact, one may argue that the presence of retrotransposons in a genome is an important marker of some ancestral retroviral infections (since, of course, the loss of the env proteins would select for their retention in the host genome). That said, amoebozoan genomes do have families of retrotransposons, complete with LTR, polymerase, and high transcriptional activity – and transposition has been observed in a few cases. Is that sufficient proof that “protozoa” have retroviruses that infect them?

Jacob writes:

Hi everyone,

I’m rushing to write this email before you start recording the next episode, because I just finished listening to last week’s podcast and I wanted to get some follow-up comments/questions in.

Quick background: I usually try to avoid emotionally-charged discussions on social media, but recently I saw a post from an acquaintance that scorned flu shots. My response led to a Facebook debate (see attached screenshots – edited for privacy of the others involved) in which I was horribly outnumbered, and ultimately left me feeling pretty hopeless about changing public perception of vaccines.

When I started listening to TWiV 217, I was really excited and hoped that there would be some additional material for me to make my case to the layperson. A good portion of your discussion (i.e. the increased cases of narcolepsy post-vaccination) would only be further misunderstood if I sent them a link to the podcast. While you guys eventually did make sure to say that vaccines are a good thing, you did it in such a way as if it was obvious to you and didn’t offer much of an argument for that point.

Unfortunately, it seems like there are many misled people out there for whom those statements are much less obvious (and apparently even seem like part of a conspiracy theory, again, see attached screenshots). So my question is this:

How do you go about trying to convince people who are uneducated about viruses and vaccines (or who have been victims of misinformation and sensationalist media) about the importance of vaccination, especially in the case of flu shots where the rate of protection is not as high as with other diseases? Do you even bother?

I was honestly really hoping there would be some sort of video pick of the week that is short and convincing that I could share, because I feel like that would be the most effective medium for convincing the average social media user.

Thanks for your help and for all of the podcasts! I really enjoy listening to them while working in the lab.


About me: I’m a 5th year PhD student in Chemical Engineering at RPI in Troy, NY, studying the design of inhibitors for HIV and influenza viruses.

Justin writes:

Hello to the TWIV team and guest(s)! I am wading my way through the long and wonderful TWIV archives since I didn’t start listening until about TWIV 170 and I have a question not directly related to a specific episode but just a curiosity that arose. During the learning period of the immune system I wonder if it’s possible to expose the developing organism with antigens to a pathogen that would cause the mouse or other organism to recognize the pathogen as self and allow for an infection with little or no immune response. Would there still be innate immunity and to what extent would the immune system be able to respond? I know this is more of a immunological question, but I am curious on your thoughts.

On two side notes I first wanted to share everyone’s sentiments and thank you all for this wonderful podcast and I have a listeners pick. I do not know if this has already been chosen but there is a great store at I personally have the playing cards had the temporary tatoo and the helix tie. Enjoy!

Stephen writes:



Rie writes:

Hello, professors. Here is to say thank you for your wonderful podcasts and letting you know that you have a fan from North Island in NZ too.

I am a Japanese female, now living in NZ, married and a mother of two kids. I have no academic background on science but have always loved to read about science. I love reading, loved adventure and fantasy stories when I was a kid. When I discovered science fiction, I totally immersed myself in that fascinating world. My primary motive to study English was so that I could read science fiction in the authors’ own language (although Japanese translators are doing marvellous job and nothing wrong with reading them in Japanese). When I discovered podcasts, I immediately fell in love with them too.

One of my first subscriptions on the iTune was “Futures in Biotech.” The episode Professor Racaniello talked about flu with Mark was really informative and made me feel somewhat in control. Being in Southern Hemisphere, we were expecting that awful flu in the coming winter (meaning very soon from the time of that podcast). Before I listened to FIB episode, I received a flyer from the government, “how to prepare for flu pandemic”. It warned us that shops and public services may not be able to operate if too many people get sick, and advised us to stock up with food, water and batteries. Also, it encouraged us to set up communication and support network to arrange somebody else to look after children if you get sick. All in all, everything sounded so grim and made me very nervous. But after I listened to the podcast and did everything recommended there, I had a peace on my mind. Luckily, the flu was nowhere near as bad as expected. And twiv was added to my subscription.

In one of twiv episodes, it was mentioned that there is no definite preventive measure for flu, but I’d like to share my experience. When I was pregnant with my first son, meningitis broke out in NZ. Many children and young students fell victim to the disease. The bacteria, the main cause of the disease, were said to infect orally, and they said children and students were infected through not-so-clean cups, plates, etc. So again, hand washing was the best (and almost the only) preventive measure that we could take. Then, one of my colleagues fell sick, hospitalised, fell into a coma, and passed away. It all happened within a week. She was a senior, living alone, and nowhere near where infected cups were. I called my midwife but the only advise she could give me was to visit a doctor if I was in doubt. So again, I did the only thing I could think of. Wash everything before putting into my mouth. As well as washing my hands, I washed cups, plates and cutleries and anything I needed to touch, from the lunch room before eating. I washed my hands and face throughly when I came home. My son was born healthy to everybody’s relief, and I followed this routine faithfully after he was born. I took a maternity leave for about a year, then went back to work. When I started working again, I got a little slack with my washing routine, and got flu. At that time, I realised that I hadn’t had flu for over a year. Before that, I used to catch cold and flu four times or more throughout the year, and I thought that was just my weak immune system. I went back to my washing-everything-before-I-eat-routine, and have being successful by not getting sick so often since then. My sick leaves are consumed by nursing my kids when they catch cold. So, I am the proof of how effective hand-washing is to prevent yourself from flu.

Just a little request, please? I am now so interested in biology and want to study, I tried “Biology Demystified” It was fun reading but virus was covered in only one page. But this series is great for an amateur like me. I feel I should try chemistry and biochemistry before tackling microbiology. While I’m making a slow progress on these, would there be a chance of “Virology Demystified” coming out? Or if you have any recommendation of a self-study book on virology, about 300 pages hopefully, for non-academic, totally amateur people like me, please let me know.

Thank you again for sharing your knowledge in these fun podcasts. Yes, I now listen to all three podcasts of yours, and fascinated by the unseen world of microbes. Long live and prosper, small and big together.

Signing off.



Wouldn’t it be wonderful if we can get flu vaccine with this? If you could buy these over the chemist counter, or even delivered to your door!

Stephen writes:

Researchers opt to limit uses of open-access publications

Nature News, Published online: 06 February 2013; |

doi: 10.1038/nature.2013.12384

Shane writes:

Hi Vincent et. al,

I was still catching up on all the back episodes of TWIV, and was recently listening to TWIV #130, where you discussed 2 different Vaccinia outbreaks. As a little background, I compete in Brazilian Jiu-Jitsu, which is similar to wrestling, and also am a referee. You asked the question “why did he wrestle”, that made me laugh. People attempt to compete all the time with visible staph infections, I doubt the wrestler in question even cared if he transmitted it to a bunch of other people.

In the second case, it was specified as a Martial Arts school, and the source of the infection was not found. It is quite common for mixed martial arts gyms to have people drop in from other schools, or people in the are on vacation will stop in and train at any random school. I can see that it would be quite possible that this martial arts school had such a visitor that could have transmitted the vaccine associated strain to these people. It is not common for schools to do any background check on people to find out whether they have been in the military or had a recent vaccination.


Shane from Australia.

Mark writes:

Dear Vincent and company,

I am a dedicated follower and fan of your TWIV podcasts and, until now, haven’t felt compelled to mail into the show. I just wanted to say that your most recent guest, Dr. Anthony Fauci, was fantastic. He was insightful and interesting and I thoroughly enjoyed hearing a bit more about the clinical side of Virology. I grew up in South Africa and have a special interest in HIV/AIDS and it’s partner infections (in particular HPV) and Dr. Fauci’s insights into the subject were riveting. I really hope you get him on again.

I also wanted to say that your Virology podcasts have influenced my decision to do an undergraduate degree in Virology and Immunology at the University of Bristol (England) this year. I will, in fact, know if I have been accepted into the course in the next couple of weeks! I look forward to learning more about the subject and will continue to be an avid fan of TWIV.

Kindest regards,


Jim writes:

Something to listen to on a commute: Massive Open Online Classrooms

March 4 is the date and it lasts 60 mins. Download by right-clicking “Listen” and select “Save Link As”.



Smithfield, VA

Chris Condayan writes:

Because Google Reader is going away.

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