Steen writes:

Dear hosts,

I thoroughly enjoyed meeting most of you in vivo at ASV, having listened for nearly four years. Svetlana’s and Anne’s enthusiasm on TWiV 503 was great.

I realize that the “first all-plant-virus TWiV” thing was good-natured ribbing (and an ongoing joke), but since the topic arose I wanted to “push back” by listing just a few of the great plant-centric episodes/arcs you have recorded:

  • TWiV 402 and TWiV 70, on host manipulation by cucumber mosaic virus to attract vectors and pollinators.
  • TWiV 343 which featured counts of infection foci on leaves, analogous to the lesions on Chenopodium species [such as quinoa] that Anne described (11:14). This episode also featured jokes about turnips.
  • TWiV 459, TWiV 403, and TWiV 47 on producing vaccines in the silencing-immunocompromised host Nicotiana benthamiana (also mentioned, starting at 33:32).

I look forward to more episodes featuring plants, insects, and fungi on this and other Microbe.TV shows.

Literal-mindedly yours,


Juan writes:

Dear Vincent, Rich and Kathy (hosts of episode 503 “the greening of TWiV”). As a plant virologist and big fan of TWiV, I want to thank you for this wonderful “all plant virus episode”.

However, as a faithful listener from the very early episodes, I can tell you that the appearances of plant viruses at the show occurred more often than you may think. I started to download and listen during my commute to work, every week since 2011, and I recall vividly several episodes where plant viruses were definitely among the stars of the show.

Here is a non-exhaustive list: 24, 79, 92, 155, 268, 271, 272, 334, 343, 347, 402, 469

Anyway, even if you cannot increase the number of episodes (which will be great, indeed), we’ll keep listening and learning things from you, so thanks again.

Best regards,



Juan José López-Moya

CRAG, Centre for Research in Agricultural Genomics


Campus UAB Bellaterra, Cerdanyola del Valles

08193-Barcelona, Spain

Gopal writes:

I think it would be worthwhile devoting a TWIV to the current Nipah virus outbreak in Kerala state, India. It looks like the outbreak is subsiding (I hope I am not speaking too soon).

Here are some links: (Dead link)

Nipah virus outbreaks have occurred in Bangladesh and the neighbouring Indian state of West Bengal. But this is the first time such an outbreak has happened in Kerala, a state in the south-western corner of India, far away from West Bengal and Bangladesh. That, it seems to me, raises the question of how it suddenly manifested here.

Strangely, just two outbreaks were reported from West Bengal between 2001 and 2012 while neighbouring Bangladesh had several episodes. One suspects that Nipah cases occurring on the Indian side of the border may be getting missed.

Best regards,



Gopal N. Raj

Science journalist


Kerala state, India

Clarissa writes:

Dear Vincent and twivers,

Last Monday WHO confirmed the circulation of VDPV1 in Papua New Guinea (1 case of acute flaccid paralysis and detection of virus in stool samples from other children) after 18 years without a case. Vaccine coverage is only 61%. That’s too bad.

Brazil used to have an excellent coverage rate above 90-95%, but now it’s around 77%! Actually Brazil used to have an excellent vaccination program. All vaccines for kids are part of the national vaccine program and are free of charge in Brazil, but coverage rates are dropping every year.

I wonder if you guys could discuss the challenge to eradicate polio using IPV and OPV, and the decline in vaccine coverage over the years in several countries. In Brazil, in addition to the economical problems that affects also public health, science, and education, the change from OPV to IPV-bOPV strategy clearly parallels the lack of adhesion by the population. I also think that pediatricians and primary health care workers have not been so demanding on the importance of vaccinating children in general. Maybe because they don’t see too much of these preventable diseases… (a weird way to forget about the importance of vaccination).

My understanding is that the future scenario to eradicate polio is complicated. I understand that the use of OPV will never eliminate poliovirus from the world because virus will always be excreted in stool of vaccinated children. However, if we use only IPV, the excreted VDPVs from previously OPV-vaccinated children and even wild poliovirus imported from other countries, such as Afghanistan and Pakistan, will circulate silently, particularly if vaccine coverage is not too high. This is a fascinating discussion and I would like very much to hear the opinion of the TWIV people.


Virological regards,

Clarissa Damaso

Clarissa Damaso, Ph.D.

Associate Professor

Lab. Biologia Molecular de Virus

Instituto de Biofisica Carlos Chagas Filho

Universidade Federal do Rio de Janeiro

Bob writes:

What is the difference between HPV and HIV. “Science” has been hijacked by political ideology movements. Scientist must appease the academic complex to get grants. The academic complex is hijacked by political ideology movements.

This is all counter to the “objective scientist” model. IMHO your TWIV is a conduit of “trump hate and bitterness”. I love your podcast but it makes me sick when you deviate to political snubbing, hate vitriol and gossip. You become stupid un trusted puppets.

Why not tell us the difference between HVP and HIV? You did not hear Trump and Gates discuss this? There are no dumb questions. I have always had comfortable conversations with scientist in the R&D work place, in school, and my family. They don’t prejudge me. They present knowledge in an interesting way.

Your team’s behavior is now the norm. That is sad. Your between a rock and a hard place. I still have writings, videos, audits of Richard Feynman to hold on to.

Anne writes:

Prof. Racaniello,

I heard you say in response to a letter on the Immune podcast that you’ll talk about politics when politicians negatively impact science. I completely agree with that sentiment.  So here’s another reason to talk about politics.

These 4 GOP Senators Are Shocked that the National Science Foundation Encourages Science Education

So they are asking for an investigation.

Ian writes:

In episode 495, mention was made that a plant seems to have no motive to attract hyperparasitoids, as this would reduce the population of parasitoids.

This could reprise the earlier comment about Ebola virulence – if the parasitoid is prone to unstable populations, the plant being able to control its population by hyperparasitoids could modulate the virulence of the parasitoid in order to promote its even distribution.

This perhaps is not likely, but is a fun thought.

Enjoying the show.

Ian, from a very sunny Scotland at 18C.

Jean-Francois writes:


Quick note regarding episode 494 (you might have corrected in 495 and received tons of e-mails about this already). rVSV-ZEBOV, the Ebola vaccine, was created by scientists at the National Microbiology Laboratory in Winnipeg, Manitoba, Canada, which is part of the Public Health Agency of Canada. It was then licensed to NewLink Genetics which licensed it to Merck in 2014.


Jean-François Gélinas

Postdoctoral Researcher

Prof Amine Kamen’s Laboratory

Department of Bioengineering

McGill University

Tom writes:


Regarding a frequent TWiX discussion topic, here’s further discussion, and some history, regarding research publication.

– Tom in Austin

Jolene writes:

Greetings TWiVerinos:

My husband forwarded me this very sad article about vaccination behavior in pet owners in the UK. In it, the British Veterinary Association issues a statement that dogs do not develop autism. Apparently, pet owners there and in the US are declining immunizations over just this concern. I was relieved to see no indication that the rabies vaccine is also being given less. Guess I will add pet owners to the list of individuals that it is a good idea to bring up vaccines with in regular conversation.

Full article link:

From the household with three pets and two humans fully vaccinated,