Xandur writes:

Hello TWiV-team,

I enjoyed the latest episode 459 especially the polio part.

I’ve been working with this vaccine and developing new ones.

As with aircraft crashes there is not a single thing going wrong, but a series of small things end up in allowing Murphy to wreck havoc.

Some links to the companies with recent problems in keeping containment:

From the paper you covered first (English below on site)


Another earlier incident



The WHO limits the amount of manufacturers of wildtype polio. Currently there are 4 worldwide with a license to produce wildtype based vaccine and no new ones will be issued (GSK, Sanofi, SII – Bilthoven Biologicals, AJ Vaccines A/S former Statens Serum Institut ). As you stated a lot of research is being performed in new vaccines such as a Sabin-based vaccine as mentioned as well:

A progress report on this https://www.ncbi.nlm.nih.gov/pubmed/27720268



Also new polio strains made by the CDC and NiBSC (MacAdam) are being tested as alternative (genetically weakened)

All in all the capacity of polio-vaccine production currently is too low too keep up with demand, new vaccines are needed, but we cannot wait on them.

The need for more stringent containment is clear, but left by the WHO to the local governments to implement on their timetable. To make matters worse new vaccine-concepts based on GGO are now already made a BSL3-agents while the wildtype still remains BSL2.

So near eradication, we need to keep up the work and accept some risk

With kind regards

Steen writes:

To my favorite pedants:

I enjoyed the discussion on TWiV 459, especially circa 47:00. Props to Vincent for referring to N. benth [Nicotiana benthamiana] as “tobacco-like” rather than calling it “tobacco” (N. tabacum). I appreciate his careful use of terminology, including avoiding reference to “expressing proteins” in plants.

The polio vaccine paper you discussed on TWiV 403 used N. tabacum proper, plus lettuce. benth was originally adopted for research use because of its nice broad leaves and because of the broad virus-susceptibility of a particular strain. This susceptibility is associated with loss of function of an RNA-dependent RNA polymerase involved in silencing amplification. The mutation appears to confer advantages in desert habitats—see the recent study by Bally et al. (pmid 27251536). The paper is not open access, unfortunately, but is accessible at http://rdcu.be/vXzQ

See also the accompanying News and Views piece: http://rdcu.be/vXzT

I have never heard of transmission of Agrobacterium by an arthropod vector; It is a soil bacterium. Many strains lack the Tumor-inducing plasmid carrying the opine synthase genes that plant cells are “hijacked” to express, for the metabolic benefit of the microbe.

Unfortunately, the floral dip stable transformation method that Kathy mentioned (Clough and Bent 1998), does not work for most plants, probably because their female germline is less accessible than it is in Arabidopsis thaliana flowers.

I believe that Caliber Biotherapeutics (which Dickson visited and also linked to for his pick of the week) has been renamed to iBio Inc. (http://www.ibioinc.com/ibio-technology/overview; see also this Beck group page).

Note the potential for confusion with iBiology.org, the makers of those wonderful science videos.

Agro-mediated transformation is not the solution to all problems. Viral vectors are still important, as evident in this news story from a few months ago:https://www.wired.com/2017/04/save-floridas-famous-oranges-scientists-race-weaponize-virus/

Damage from Irma recently added to the economic losses from the citrus greening crisis described.

Best wishes,


Hamish writes:

Hi Vincent, Dickson, Alan, Rich and Kathy,

Greetings from a semi clouded Amsterdam, 17C (go metric US!) , with a few spots of blue sky here and there. A light breeze, an enjoyable autumn late afternoon.

I’d like to mention that in the dutch news coverage the operator was identified as being male.

The company is called Bilthoven Biologicals which mentions the incident on its website (english version at the bottom of the page). http://www.bbio.nl/nieuws/2017/april/medewerker-besmet-met-poliovirus

New items:



(Google translate does an ok job on these.)




ps.1 While I am not an academic, I still enjoy listening to twiv a lot. Thanks for making virology and science in general a bit more accessible to me.

ps.2 Vincent: the dutch ‘stad’ sounds more like ‘stat’ though, your version has a more german feel to it. Anyway, not half bad, considering the way you butcher the names of the authors 🙂  The ‘ui’ sounds is difficult 🙂

ps.3. Dickson(?) The Netherlands is small but Bilthoven and Amsterdam are still 50 km apart. With 20K inhabitants, it’s not considered a hotspot for transit traffic e.g. tourism.

RP writes:

Re: Alan Dove and Rich Condit’s disingenuous response/topic hijack

Dear TWIVians –

The weather here is 64 degrees F and partly cloudy – cool enough to open wide the windows in the library and enjoy the sounds of the birds.

I am a great fan of the shows – in fact, I subscribe to TWIV, TWIP and TWIM so I keep up my end for your numbers.

Forgive the temerity – but just in case you or your listeners are not aware, certain podcast platforms often unsubscribe listeners who are late to listen (2 episodes piled up unplayed trigger an unsubscribe) – so I always make certain to keep an eye out lest my schedule trigger an unwarranted drop from the feed which will negatively impact the ad revenue.

Even as a young child I was raised to be unbearably conscious of revenue to production costs being directly proportional to stress free days and night.

That said, these specific podcasts are special to me – and I thank you all for your hard work and dedication – and the hours of edutainment you provide.

I write today because I have grown to respect the panel and was disappointed to hear what I must consider a classic misdirect as to the issue of organic versus non organic food.

To pretend the question is one of nutritional equivalency is to ignore the fact that one is laden with pesticide and one is not.

To proclaim that it is more efficient to slowly poison the population who live near the farms and poison those who eat – to consistently sicken actual farm workers exposed to poisonous pesticides is such a dark ends justify the means dismissal I prefer let you all follow that thought to its conclusion.

It is a shame that our organic labeling laws are riddled with work arounds – but that does not make the concept of organic simply a marketing ploy.

As for the GMO labels – I am as frustrated as any educated consumer who sees “non gmo verified” labels on foods – especially when most labeled have no corresponding GMO on the market.

I am even more frustrated by those around me who are afraid of science or believe they can simultaneously care for their health whilst ignoring the science and scientific methodology.

It is even more personal for me than for most – I am a person who was recently legitimately diagnosed with allergies to a couple known chemicals by an actual panel of real medical doctors – as it turns out, the chemicals are commonly used as biocides, preservatives, pesticides –

This was no easy task.  Quackery abounds.  More time, tests, and money, ad hoc research and loss of life quality than I care to mention.

Listening to TWIV helped me through some painful, sleepless nights – but I digress.

When it is posited that labeling for cholesterol or carbohydrates is more important than labeling for pesticide – or labeling for peanuts is more important than labeling for pesticide, preservatives or biocides is to ignore the science.

I am not alone.  In fact, one of my allergies is more common to laboratory professionals and others than many would like to learn.

Unfortunately for our undereducated letter writer, he is also wrong on certain crucial points.

Organic is not “kinder” – organic can mean no pesticide grain fed to animals which endure torture.  There is no animal welfare rating attached to the label organic.  Organic food can be harvested by slave labour.

Organic is kinder to the farmers and the farm workers only in that there are no pesticides poisoning them – and last I checked, it was kinder to keep them in the field working rather than in the emergency room or the “insert illness of choice here” ward of the hospital and out of the grave.

If pesticide purveyors were forced to pay the health care bills and environmental clean up costs and to handle the logistics of administering the care and the clean up – they would not be efficient.

Perhaps someone on the panel would like to do the math on that.

Thank you again.

Alexander writes:

Dear TWiVers,

I am a microbiologist researching Brucella in Berlin, Germany. The weather today switches between rainy and sunny back and forth, 13°C (55.4°F), humidity 89%. Winter…ah…Autumn is coming!

I count myself to the group of more recent TWiV listeners, so I am catching up some past episodes to get settled into the podcast. In TWiV 455: “Pork and Genes”, Kathy Spindler mentioned something concerning severe viral respiratory infections in children with IFIH1 mutations, which struck my philosophical side. She said, children with this mutation “May have something genetically wrong.” and I am pretty sure all of us understand what she is really meaning by that.

Nonetheless did I ask myself, if we as scientists should judge. I feel like calling this mutation “wrong” is not appropriate. It’s probably a regular part of the human gene pool. No one really knows a) if it might once have been the wild type and b) if people might have some other benefits from it. I am aware that this example is extendable to recognized illnesses as haemophilia or red-green color blindness, which might complicate the matter a lot.

Do not misunderstand me: that the IFIH1 mutation leads to children going to ICU is awful, but classifying mutations as “good”, “bad”, “wrong”, “right” or else tends to add a moral point of view, which I am not sure if it suits a scientific evaluation, as it is not neutral. In the end, people and their genomes are different. The world would be a very sad place if this were otherwise.

I hope I could get my message across.

What are your thoughts about that? Are we able to judge or classify? Should or shouldn’t we? Must we?

Keep up the good work!

Best Regards,


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