Zach writes:

Hey Twiv Team!

Reporting from Woodbridge, VA. The weather is currently 64°F and 4°C, humidity at 50%.

I am somewhat of a recent listener. I started in January 2016 and have been working my way through some of the backlog of episodes. I really enjoy the show. I am currently taking an infectious diseases course focusing on viruses and this show has been very insightful. I appreciate the knowledge and perspective of all the team members (including guests).

I recently had to present on Zika virus and found this podcast helpful in stirring ideas.

I was curious on everyone’s thoughts. I came across an article talking about what was making Zika virus worse in the outbreak in the Americas than previously reported in Asia and Africa. Dr. Michael Diamond at Washington University and officials at the World Health Organization were theorizing that individuals with previous Dengue Virus infection were more susceptible to severe Zika virus ( Is this theory more likely than possibly a lack of immunity of individuals in the Americas or possible mutations with ZIKV considering many of these side effects were not reported before (whether not taken into account or simply not there)?




Paul writes:

Just wondering why the NYTimes says “the virus mutated from an African to a pandemic strain a decade or more ago and then spread east across the Pacific from Micronesia and French Polynesia, until it struck Brazil,” while the merry twivsters say there is no evidence at all for  such a “theory”. Could this be another example of journalistic catastrophizing?

Sean writes:

Good afternoon Professors,

My good friend, a fellow public health graduate student, shared this MMWR article with me about male to male transmission of Zika virus in Dallas. I remember from the past few TWIV episodes featuring this “en vogue” virus that it was still unclear whether or not Zika was transmitted sexually. Perhaps this article will garner more attention from other reproductive health enthusiasts such as myself.

It’s a lovely 25 degrees Celsius (77 degrees Fahrenheit) with blue skies here in Los Angeles. Wishing you all a warm Spring day and kindly requesting any melted snow to be sent to our mountains so we may continue to recuperate from our drought.

Sincerely yours,


Ted writes:

Probably the first of many reports to follow in this population and adding to the Zika story.

Continued thanks to you, your regulars and guests for the always informative podcasts.

Ted Splaver DMD

Adjunct Faculty, NOVA Southeastern University, Davie, Florida

Stephen writes:

Dear Twiverati,

I have to say that, while I was initially skeptical about Zika sexual transmission, I’ve been won over and I’m surprised that you’re still skeptical. (Caveat 1. I’m a layman, although TWIV and other sources keep me informed. Caveat 2. I had the pleasure recently of hearing Dr. Brian Foy talk about sexual transmission of Zika).

One thing that I haven’t noticed you cover yet is the sex disparity of non-vector transmission. These cases are from males to females (and in this week’s MMWR, from a male to another male). If the non-vector transmission were from something else (say, exposure to rashes), one would expect a two way transmission. But having it be just from males (or even if the preponderance of transmission was from males) makes sexual transmission the easiest explanation.

One thing Doctor Foy pointed out that makes him think sexual transmission is common is that, in earlier outbreaks, there is a noticeable sex disparity in some of the earlier outbreaks where more women than men were infected.

One other comment, more a minor correction, though it has some bearing on the debate. I heard Alan say in one episode that the cases of alleged sexual transmission were all apparently transmitted during or shortly post the symptomatic period. From Dr. Foy’s original paper: “Furthermore, patients 1 and 3 reported having vaginal sexual intercourse in the days after patient 1 returned home but before the onset of his clinical illness.”

It’s warm right now in Fort Collins, but we’re supposed to get snow over the weekend.

Thanks for all your hard work,


Steen writes:

Dear Vincent and friends,

Thanks for reading my message and discussing the cowpea mosaic virus paper (TWiV 380). I love hearing about the history of structural biology.

For what it is worth, Hull writes that “Of the 92 plant virus genera, 36 have multipartite genomes” and that “many” of these genera include multicomponent viruses (genome segments packaged separately). Hull lists multipartite genome structure as one of at least twelve strategies for increasing accessibility to the host translation machinery.

I don’t really need a textbook (41:30)—I borrow an old edition from the library sometimes—but I look forward to future contests. I’m planning to graduate and move away soonish—I need to avoid accumulating more heavy books.

Regarding Jared’s question, I poked around a little, but did not find much about orchid symbiont viruses.


Ricardo writes:

Hello TWIV friends.

A phage, in order to infect a bacteria, needs a “key” to open its access. What if that “key” gave access to multiple misfolded proteins such as amyloid beta and led to its destruction…

Viruses can be our friends.

Ricardo Magalhaes, Ph.D.

Associate Professor of Microbiology


Faculty of Health Sciences of Fernando Pessoa University



Helen writes:

Dear TWIVome,

I’m a PhD student at the Novo Nordisk Foundation Center for Protein Research at the University of Copenhagen, and my work focuses on bioinformatics methods for inferring virus-host protein-protein interactions. I discovered TWIV after finding Vincent’s virology courses on youtube, started listening, and now I look forward to new episodes. The lectures and TWIV have been invaluable starting points for me to locate background material on virology, and to keep up to date with advances in the field. Thank you for your outreach!

Vincent mentioned in passing in TVIW 380 that there was some evidence that mimivirus infection was beneficial for its natural host. I’m unable to find more details about this beyond those that apply broadly to all DNA viruses, even after checking page 2 of Google and previous TWIV episodes tagged with symbiosis. Could you point me to a reference?  I would be very interested to read more.

Best regards,


Anthony writes:

The Link is on Climate Change Denial, but it’s struck me that the anti-vax sentiment is something that can be investigated via Psychoanalysis. Some months back, a Google search showed no results.

The Institute for Psychoanalysis is in London, England, but the APA is here:

American Psychoanalytic Association

309 East 49th Street, New York, NY 10017 | Phone: (212) 752-0450 |

Perhaps it might be suggested to the APA that anti-vax belief might be an interesting topic for a Psychoanalyst to research?



# # #

Institute of Psychoanalysis

We’re pleased to present the first of our new short film series, Connecting the Dots – in which we explore ways that psychoanalytic ideas can shed light on a variety of other fields.

In this interview, we speak to Sally Weintrobe, a psychoanalyst who writes, talks and blogs on Climate Change. She introduces us to the concept of Disavowal, a form of denial that she believes pervades our culture – and poses a significant barrier to taking action for the planet.

BTW, using Alice Miller’s argument from For Your Own Good, that some guy commits fraud is criminal, but not exceptional. That many thousands — against all reason — continue to believe the fraud and rally behind the trickster is something significant.

Bridget writes: 

Hello Drs. Racaniello, Despommier, Dove, Condit and Spindler,

It is 37 F (3 C) and overcast while I am writing from Columbus, OH.

I am a relatively new listener to the program, but I am hooked already. I value your insightful dialogue and in-depth discussions about current research in virology. Since graduating from undergrad at Ohio State last summer, my life has been relatively void of conversations involving molecular biology of any sort. I missed those discussions enough to turn to youtube as a learning tool, where I discovered  Dr. Racaniello’s introductory virology class. Within 2 months I had watched all of the 2014 lecture videos, and had begun listening to TWiV.

Prior to watching those lectures I knew that I wanted to pursue biomedical research, but was struggling to identify a specific area that I was passionate about. That changed quickly; after each new lecture I found myself wondering a million things (most of which haven’t been answered yet). Because of my incessant curiosity I am now quite convinced that I want to study virology in graduate school and beyond.

In researching various PhD programs I have become a bit overwhelmed (in a good way) about the wealth of viral research occurring in the world. I am writing you all for some advice. Currently, I am extremely interested in the various oncolytic strains being developed. However, some researchers I have spoken to have given me the impression that this area of research has many drawbacks, and may not be a wise choice of research topic. I tend to enjoy more molecular biological based research methods to biochemical assays. And, I greatly appreciate research that goes towards understanding basic molecular biological systems rather than specific outcome based research (i.e. anti-retroviral drug development) but I am pretty flexible there.

Are there any areas of research that you all are particularly interested in/ seem promising? Are there any areas that seem to be less viable? Who are some up and coming researchers in the field that would be worth keeping an eye on? Do you have any advice for choosing a PhD focus/ program?

Sorry for such a long message, thank you for taking the time to read it and think about these questions. Also, thank you for your slightly skeptical analysis of each paper that you present. Since I began listening I find myself more willing to trust my instincts when something I read in a journal article seems overblown or speculative. The ability to evaluate claims is fundamental to research. Your weekly discussion gives me a model for what that process looks like among practicing scientists. As someone who is just starting out that is extremely valuable to me, so thank you.

Best of luck in all of your future research,


Rhys writes:


I’ve recently discovered your channel and it has been helping me with my Virology revision! I have a couple of questions:

– Do you have a references for:

  1. Adenovirus protein VI destroying the endosomal membrane thus allowing entry into the cytoplasm

[PMID 25798531 ← a review; 2005 Wiethoff…Nemerow: 15681401; another paper from Wiethoff: 2010 20409568

  1. Poliovirus generating the pore-like structure allowing genome entry into the cytoplasm

Danthi P, Tosteson M, Li QH, Chow M. 2003. Genome delivery and ion channel properties are altered in VP4 mutants of poliovirus. J. Virol. 77:5266–5274. 10.1128/JVI.77.9.5266-5274.2003.

Tosteson MT, Wang H, Naumov A, Chow M. 2004. Poliovirus binding to its receptor in lipid bilayers results in particle-specific, temperature-sensitive channels. J. Gen. Virol. 85:1581–1589. 10.1099/vir.0.19745-0.

Also, what do you think are some of the major similarities and differences between the entry of enveloped and non-enveloped viruses?

Ted writes:

Dear TWIVers,

As a listener pick, I suggest, Turning The Pages Online ( the pages/) for viewing, The Marshall Nirenberg Charts:The First Summary.  

This NIH/National Library of Medicine Project features 10 lab book images and information on the remarkable career of Marshall Nirenberg (1927-2010) who shared the 1968 Nobel Prize in Physiology or Medicine with Robert W. Holley and Har Gobind Khorana, “for their interpretation of the genetic code and its function in protein synthesis.”

Especially noteworthy is the included reprint of Nirenberg”s Science Editorial of 11 August 1967, entitled, “Will Society Be Prepared?, which contains his prescient concern about the future resultant manipulation of human genes.

The concluding paragraph begins, “The point which deserves special emphasis is that man may be able to program his own cell with synthetic information long before he will be able to assess adequately the long-term consequences of such alterations, long before he will be able to formulate goals, and long before he can resolve the ethical and moral problems which will be raised.” He concludes, “I state this problem well in advance of the need to resolve it, because decisions concerning the application of this knowledge must ultimately be made by society, and only an informed society can make such decisions wisely.”

We have obviously entered this debate with the advent of CRISPR/Cas9 and other methods of gene alteration/engineering which you have discussed on past episodes, and of note are the April 11 Wall Street Journal article, “Should Heritable Gene Editing Be Used on Humans,” with the pro stance written by George Church, professor of genetics at Harvard Medical School, and the opposing con article written by Marcy Darnovsky, executive director of the Center for Genetics and Society.

Additionally, the April 14, 2016 NEJM Perspective article, entitled, “The Public and the Gene-Editing Revolution, by Robert J. Blendon, et al,  (attached and open-access) discusses the public’s present view on gene-editing.

Again, many thanks from sunny Florida- present temperature 84 degrees F- for continuing to brighten our days with your wonderful podcasts which continue to provide an excellent window into the scientific literature and knowledge advances.

Ted Splaver,DMD

Adjunct Faculty, College of Dental Medicine

NOVA Southeastern University, Davie, Florida

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