Matt Frieman writes:

I met Hillary last year when he gave a “final lecture” at the Institute of Human Virology here at Maryland. He is old friends with Gallo apparently. He told a hilarious story about why he didn’t feel bad that the vaccine for polio is called the Sabin Vaccine. He said he would hate for parents to take their kids to the doctor and ask for the Koprowski vaccine and then make kids cry when they got the shot! He would much rather them cry about Sabin than Koprowski.

It was nice to meet him before he passed. A big name and good man.

Liam writes:

Hi guys,

I just wanted to send you my thoughts on the HeLa sequence controversy.

The entire HeLa sequence was (and remains) available from other studies. For example much of the ENCODE project, the most thorough mapping of the genome to date, was done in HeLa cells and that data is all available online. EMBL did their sequencing to establish a reference genome for HeLa cells. Generally researchers align sequencing results to the reference human genomes but, as their paper documented, there are so many alterations to the HeLa genome that it is different enough to merit it’s own reference genome. I don’t know how this should impact the discussion, but I do think it is important information. Whatever your feelings about the data takedown, this raises a lot of questions for proponents (myself included) of open access and open data publishing.

I always like it when you guys discuss these pan-discipline topics, keep up the good work


p.s. I kind of liked it when you called follow-ups F-Us, and I’m surprised anyone took offence to the implication of a swear word in an in informal conversation amongst adults.

Kathryn writes:

An young ha say yo TWIVers (that’s hello in Korean)

All is well this evening, the cherry blossoms are out and we’re expecting highs in the upper 60s, about 19C.

On TWIV 227, Vincent and Kathy discussed a figure showing the sialic binding sites in the human respiratory tract, including the eyes. With the outbreak of human cases of the bird virus, H7N9, is it possible virus is getting into the respiratory tract through the eyes. As they described in the figure, there are alpha 2,3 receptors in the eyes. I can envision a situation where a person in killing a chicken for a customer and blood or other bodily fluids spray into the eyes or inhaled.

Just some naive thoughts,

Stephen writes:


I just wanted to offer a word of praise for Denise Grady, of The New York Times for including these sentences.

> Researchers are not sure how deadly it is because they do not know how many people have been infected. The worst cases become obvious, but if some people have mild symptoms or none at all, many cases could go undetected.



> Cox notes the virus already has two genetic changes that enable it to infect human cells and reproduce at human’s body temperature, which is lower than birds’.

> That means, she says, “these viruses may already be partially adapted — not totally adapted, but partially adapted — towards the type of virus that might efficiently transmit from human to human.”

This comment by CDC’s Nancy Cox, as quoted by Richard Knox on NPR, brings up a question. Let’s say five changes are necessary for a wild-type bird flu virus to become a dangerous human flu virus. Reporters usually write as if genetic change 1 predisposes the virus to acquire genetic change 2, and 1 and 2 make it more likely that 3, 4 and 5 will occur. They also usually report that such changes are always one way. Once 1 is acquired, it’s never lost.

Is this true? Is it any more likely that a virus with mutation 1 would gain mutation 2 than that it would lose 1? Is Cox’s implication true? Do the mutations for a zoonotic infection make it more likely that the new H7N9 would become able to transmit between humans?

Rui writes:

Dear Vincent,

I am a student from University of Edinburgh in Scotland, also a regular reader of your great blog. I actually have some quite stupid questions to ask you.

I read some news for example this one in Nature ( ), basically people concern about the human-human transmission of the novel H7N9 avian influenza virus. But what I am confused at is the definition of H2H transmission of a flu virus, what is required for a flu virus to be transmitted effectively in human? And what is the boundary there lying between the zoonotic transmission and H2H transmission?

Does H2H transmission mean wherever the flu virus acquires its segments- ??

1, some certain types of cells are permissive to the flu virus: the virus can enter the cells and replicate efficiently.

2, the progeny of the virus is able to be present in the aerosol produced by the human host which is able to infect the other individual.

If I have a strain of H7N9 virus, I infect human A549 cells and get a very good titre from plaque assay, what does this mean? does this only mean A549 cell is permissive for the H7N9 virus?

Many thanks



Georg writes:

Hi TWIV-Team,

I discovered your netcasts via Omega-Tau (a science netcast by Markus Völter/Nora Ludewig), when you did a joint episode on viruses there (July, 2011).

Currently, I am at TWIV episode 191 (I started from episode 1 in chronological ascending order). I also enjoy TWIP very much.

I don’t know if you are already aware of this netcast distribution site:

Basically it is a web-service for making netcast distribution via P2P (bittorrent) easy for publishers – while providing a comfortable directory for listeners.

It is a community-driven project by netcast-enthusiasts – it was started by a german developer who is connected to Tim Pritlove (… thus the name…) – who is probably the most famous german netcaster.

Omega Tau is already there:

I don’t know if you pay much for your bandwidth or how much it is saturated when you release a new episode – but P2P technology would

certainly help with that (i.e. saving your own bandwidth and improving scalability).

Besides the technical advantages (and interesting technical details) the directory has grown into a collection of great netcasts such that you probably would attract some new listeners there.

I (for example) have discovered many nice netcasts there, which I would have probably missed otherwise.

Best regards

Laura writes:


I am studying for a PhD in the UK and i was wondering are there parasites of parasites?


Randy writes:

love the podcasts, they have been entertaining and very helpful in my epidemiology class. Thanks!

Kathryn writes:

Hi TWI* hosts. I’m writing from dark South Korea where it’s 46F, 8C at 8 PM.

I don’t have a question per se. I want to confirm a piece of knowledge that I hope I’ve picked up since TWIV 1. People, cells, cell cultures and animals are all different. So take H5N1 flu. People react one way (anywhere from mild respiratory infection to death). In cells you can [have] the H and the N working their magic (cutting off their hands, but just slowly enough as Alan described in a few TWIVs ago). Then there is cell culture. When you talked about lung cell culture and how it stratifies to resemble actual lung tissue you might (please correct me if I’m wrong, but this is where I’m fuzziest) expect full-on virus production if using a human-adapted virus. And as we saw with the ferret experiments, animal models are not human. You may or may not see the same behavior. In any case, symptoms of the disease are likely to be different (weight loss in mice with flu).

As an aside, you spoke of how things have changed in terms of techniques in your field. In my former field, infant perception and cognition, things haven’t changed much since the 50s.

Thank you for you time in reading this letter. And if it’s off the deep end, feel free to send it to the electron recycling plant.

Joseph writes:

Dear TWiV Mavens,

As a chemistry graduate student at your university, Professor R., I took a cumulative exam that required us to fill in a blank periodic table, so it is not unheard of. Though Alan’s point about lazy testing may well have played a role.

The only hard parts were the metals for me–any organic chemist should be able to fill in the Main Group. But to be a good inorganic chemist, it really helps to know your way around your section of the d and f blocks. The professor had given that test before, so we were able to cram for the day. I certainly couldn’t do the d and f metals now.

BTW, my thesis advisor at Columbia, Ron Breslow, was a Westinghouse Science Talent Search finalist in high school (as was I).

All the best,


Rob writes:


My name is Rob Lambkin-Williams and you mentioned me on your podcast a few weeks ago in the context of the viral challenge studies that we conduct (Flucamp) .

I wondered if you would like to visit and let me show you what we do and why it is so important ?



This email was sent from a mobile device with an annoyingly small keyboard, apologies for any typos

Rob Lambkin-Williams BSc, PhD, MRPharmS


Judi writes:

TWIV gurus,

First, thanks again for the time you all spend on TWIV, TWIP, and TWIM .

I have written before – I am a high school science teacher in San Diego, CA (sunny, 19 degrees C ) and wanted to write to you about two topics in this week’s TWIV.

First, if you are going to talk about science education, check out the Next Generation Science Standards (NGSS), the putative science standards for K-12 grades under the common core education banner [ – click on NGSS standards button at top of page].

The common core standards are standards that have been adopted (in theory) by 48 states (not Alaska or Texas) and are designed to that all the states in the US will be teaching and testing the same material. So far the English and Math standards are being implemented, and the science standards are on their second major revision. If you look at these standards, you’ll see that many teachers, myself included, are worried about the lack of basics required and the potential lack of rigor. ( For instant, stoichiometry will not longer be required for high school chemistry – it is recommended. Scary to think what will happen to kids in college bio and chem classes if they can’t balance equations!)

I bring this up only because if you have a program in science education, please get people who are familiar with NGSS, as these are the standards that will guide K-12 education for many years into the future started 2015 or 2016, depending upon when they are completed.

Second, in episode 225, you also mentioned a need for basic cell bio podcasts/videos to help people understand some of the basics. Since I am about to embark upon teaching honors biology and a biotech course in high school, I planned to start on a collection of just such type of podcasts or screencasts this summer. I have been trying to decide what subjects I should pursue, and since you have a collection of great minds and experienced professors, I wondered if you would give me some suggestions for topics you think would benefit both my students and TWIV listeners. I will be happy to share these with you if they live up to the standards of TWIV…. I’m new at this but I think this is an important way to reach students and individualize instruction.

Thanks for all the ideas you’ve put in my head…

Mike writes:

Hello folks, from an avid listener.

Towards the end of episode 224, there was a discussion of the periodic table of the elements. For a while, I’ve had ‘Chemistry in its element’ from the UK’s Royal Society of Chemistry in my podcast subscriptions. When the series began, the presenters went through the periodic table, giving a five minute or so summary of the element’s history and uses. Since reaching element 118 in 2010, the podcast shifted to chemical compounds, keeping the weekly release cycle.

If you want only the original series, on the elements, go to

There’s an iTunes feed on that page, which can also be used as an RSS

feed by removing the leading itpc://

The series on chemical compounds is at

and an RSS feed is at

which is the same feed as the iTunes link above, but with http:// substituted for itpc://

If you read this email on a show, just call me Mike in Florida, rather than trying to pronounce my last name.

57F, 14C now in Daytona Beach, with clear blue skies.

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