Bonnie writes:

Hi Vincent and crew,

I would really love to hear you guys toss around this newly published commentary. 

Seems spot-on to me as we continue to see waning neutralizing antibodies in the setting of epidemiological evidence of persistent protection against severe disease after vaccination and/or natural infection (in the vast majority).

Perhaps the mRNA vaccine technology is even better at inducing strong T cell immunity than we realize.  These authors certainly make a good case that measurement could serve as a better correlate of immunity. 

The authors suggest that at the very least we need more research in this area of T cell/memory immunity.

Thank you as always for your amazing podcast. Please keep up your great work for all the fans like me! 


Bonnie Offit 
(pediatrician and Paul’s wife)

Agnes writes:

Dear Heroes of Twiv and Microbe TV,

I am a longtime listener and wanted a reason to share my admiration for you and the education you provide. While this is my main reason, I also wanted to include a gentle correction on what Rich Condit said about oxidation and reduction in TWIV 873. I believe he mentioned “reduction of primary alcohols to aldehydes”. The first time I heard it, my chemistry senses tingled and I played it back for confirmation. When I think of reduction with my students, I think of adding a hydrogen to an aldehyde to become a primary alcohol. You can also look at it mechanistically and imagine an aluminum hydride donating a negatively charged hydrogen (also known as a hydride) to the carbonyl carbon of an aldehyde. This changes the C-O double bond into a single bond and a negative charge resides on the oxygen. The resulting alkoxide ion becomes a strong enough nucleophile to donate its electron pair on the oxygen to a hydrogen on another molecule, like an alcohol such as ethanol if it is a solvent, to produce the resulting primary alcohol product. There is more to this but at least on this level, it makes sense to me. Hope it helps!

Please accept my deepest appreciation and gratitude for your valuable knowledge. When Rich and Kathy mention “for the uninitiated listeners”, I feel they are speaking directly to me. They as well as all of the TWIV/Microbe TV team have opened up new worlds of learning for me. I only know chemistry having received my doctorate in inorganic chemistry (with emphasis on crystallography). Hence when you described the structure of mimivirus’ nucleocapsid, I was silently saying, “More, more, I want to hear more!” Absolutely loved it.

Sincere apologies for the length of this. Feel free to edit. I wanted a chance to thank you all and contribute my 2 cents!

Agnes Lee, Ph.D.
Chemistry Learning Center
Medical Sciences Center
Madison, WI

Deborah writes:

Dear Vincent and friends,

Thank you so much for all the education you’ve given me over the course of the pandemic. As someone who lived through SARS in China and in my role at the time at the US Embassy helped the CDC with its deployment, it never occurred to me that we would be so unable to implement basic preventive measures. After all, it was US CDC that worked with their Chinese counterparts on track and trace. The Chinese have since become masters of it, and it turns out we never were able to do it ourselves. Listening and learning from you about what is working and not has been incredibly helpful.

I wanted to address a few things from your most recent episode as someone who lived in China for 18 years and specializes in Chinese environmental politics. Firstly, the use of game animals as a term related to China is what the authors of the first paper say it is – it is about animals that are basically captured from the wild and while generally farm-raised for all or part of their lives are not fully domesticated. You all then digressed into hunting and African bushmeat and US deer and elk and the like. Hunting as such doesn’t have anything to do with the wild animal trade in China. For one thing, no one has guns. In my 18 years in China I once met a German aid worker who said he went out and hunted wild boar and pheasant for his food, but that was incredibly unusual, and I’ve never heard about it otherwise. There is a bit of touristic stuff, but it doesn’t exist as a way to enter the markets and the food industry. Thus, all of these game animals spend considerable time in captivity, which I think is an important part of the specific risk of ill health.

As for the taste for game meat, you are indeed correct that there are all kinds of cultural preferences for food. My impression is that there are cultures, such as ours, that are interested in trying new spices or flavors with the same proteins, and there are cultures like China’s that are interested in new proteins, but generally cook them the same way. Nowadays you do find people in China interested in trying Indian or Italian food, but more commonly you find people who would like to try some new variety of meat or fish but would prefer it cooked in the same way as other meats and fish. I’d also note that the US is at the extreme end for limiting meat types and becoming more so all the time. I don’t think I’m alone in having had grandparents who ate tripe and liver, which I don’t eat. And earlier generations of Americans ate things like rabbit, which is now quite rare (sorry, no pun intended).

But please call these markets or farmers markets. Wet market is a mistranslation of the Cantonese (not the language of mainland China) and seems to give people the impression these markets are different in some fundamental way from what Dickson described seeing in Thailand – they aren’t. They are a pretty common type of market all over the world. And the main issue about China is how big it is, and how large the animal husbandry market is.

As for why people purchase live animals, it is generally because they think it is a way to reduce the risk of getting bad meat – to prevent receiving an ill animal, not to cause illness. I’ve never bought live meat, but I did often go to fish markets to choose fish out of a tank when I lived in China. I may be totally wrong about the reality, but my impression and those of my neighbors was that it was easier to tell if a fish was healthy if it was still swimming around – look at how it swam. So I think that is what people are doing – they want their meat fresh and healthy. Obviously, it turns out in crowded cities not to be the greatest idea, but the motivation isn’t hard to fathom for a country that does not trust its food safety regulators and does have a huge problem with food adulteration.

Just thought I’d share a bit. I have found listening to your discussions of papers incredibly illuminating.

All the best,


Brenda writes:

TWiV 876 – What an interesting podcast!

A few of thoughts:

Like you translate Degrees Centigrade to Fahrenheit, Kilometres need to be paired up with Miles.  I must confess that I had to do some Googling of various walking distances in my vicinity to get a handle on 1.1km.

Was any study done of the workers in the Wet-market (especially in the wildlife trade and nearby stalls) – where they live might be interesting.  It might connect the cases with no known direct connection to the market. When I lived in an apartment building, I could tell you where my immediate neighbours worked, but not the rest. That would be two out of sixty units sharing one elevator.

What is the likelihood of the wildlife traders getting wind of the impending closure – and clearing out the illegal animals before the local officials got there? From my experience I would suggest the chances are that is how it played out.

Brenda, Black Isle Scotland.

Kate writes:


On episode TWiV 876: Spillover market with Michael Worobey the guest was asked if people around the market could give serum samples for testing.  He said at this point in time they would be corrupted.

I was wondering if the zero Covid policy in China might mean you could still get some good samples?  Assuming the virus got contained and maybe some people didn’t get a vaccine, couldn’t you still attempt to research this population?



John writes:

Drs. TWiV:

Last throes of winter here in Greater Braddock just like you’re experiencing.  I made a few loops around the back acre on my cross-country skis just to be able to say that I had. 

Consumption of critters:  When I was a grad student @ Rutgers, for trips back home to the DC area we only ever took I-95 once.  Forever after we’d take the back route down Rt 1 to US13 in Delaware and onto 301 thru the Eastern Shore to 50 and then across the Chesapeake.  There was a place we’d pass on 13 that always had a sign by their mailbox:  OVEN READY DUCKS MUSKRATS.   I never had a chance to experience the place since I was never tempted to try a muskrat and my ever-impatient future ex never wanted to stop for a duck, but I regret that I never managed it. 

But if someone were to come up with a way to prepare groundhog that would make it palatable to the point of being hunted to extinction, you wouldn’t find me complaining.

Then with discovery of the Endurance, which is of course enormously cool, a COVID reference:  My old W&M classmate Jerry Coyne who may be familiar to you is currently returning to Chile on a Norwegian ship that just passed close to the site of the discovery.  One of the crew on his ship knows one of those on board the discovery ship.  Jerry would still be down in Antarctica except that despite the tightest of COVID testing prior to boarding and then afterward while at sea, several passengers came down with COVID a few days after they were at sea, and the remainder of the voyage was scrubbed.  It ain’t over!

Re, the Endurance you mentioned the Vasa (which I’ve visited many times), but there’s another beautifully-preserved Swedish shipwreck, discovered more recently, that you may not be aware of.  The Eric Nordevall was a sidewheel steamboat built to ply the newly-completed Göta (pronounced Yerta) Canal (built to circumvent Danish taxation of ships sailing around the southern coast; the tax was dropped 3wks after the canal opened) that connected Stockholm with Göteborg (Yertaborry, aka Gothenberg) by taking advantage of two large lakes in-between, Vättern and Vänern (Vettern and Venern).  Things went well with the Eric Nordevall for 19yrs until 1856, when it foundered on a reef in Lake Vättern, and then abruptly sank no sooner than it had been towed free.  

If that had not happened, the Eric Nordevall would have long since disappeared from any memory, just like its four sister ships.  But it while disappeared from the surface, it didn’t vanish.  It stayed upright on the bottom, even better-preserved than the Vasa.  You can read the fairly succinct story of its past, and its discovery here.  The site is a little weird – just scroll down past the images to get to the text:

But what did they do next?  They could raise it or reconstruct it.  They chose the latter, using it as a training exercise for traditional wooden shipbuilding, in scrupulously authentic detail, and even fitted it with precise replicas of the original wood-fired steam engines, actually built in the same factory that built the original ones in  the 1830s.  That ship, the Eric Nordevall II, christened by Crown Princess Victoria, now plies the same Göta Canal in summer months as a tourist attraction. If you simply search   Eric Nordevall II   you’ll get numerous YouTubes of it, as well as articles about it including this one in the journal Industrial Archaeology.  Who knew that there was such a journal?

Since the last half of this is all about Sweden, I’ll close with the typical Swedish closing,

Med vänliga hälsningar   (med venliga helsningar – with friendly greetings)  The world could use more of that attitude.