Stephanie Langel writes:

I hope everyone on TWiV is doing well!

Firstly, I enjoyed episode 546 and the discussion of hep D in birds and snakes and coronaviruses in pigs and bats.

However, as you can imagine, I have a couple comments from the episode. Dickson… I love ya but… you were KILLING me in this episode. There are a few things that I want to help clear up.

At 51 min 0 s: Dickson states that swine feces is “more liquid than solid”. That is not true. Normal pig feces is formed and solid. If they have an enteric infection, their stool becomes softer during subclinical infections and watery, mucoid or bloody during clinical disease. Here are pictures for reference

Dickson referenced pig lagoons as his logic to why loose stool is “normal” for pigs. The reason he thinks that is because the lagoons from large farm operations look like a body of water (see picture here Hog operations that utilize lagoons for their manure management system will house animals on slated floors. The manure falls between the slates and then a water flush system pushes the manure below the slates into a lagoon. If the animals are housed on concrete, then the manure can be scraped and hosed off into the lagoon. The lagoons are a combination of manure, urine and water. They are not representative of what comes out of the animal.

At hour 1, 46 seconds : Dickson states that “the majority of pigs raised in China are outdoors”. That is no longer the case as China has made major investments in the swine industry as pork is their largest source of protein. While  ~1/3 pork is supplied from small farmers with <50 pigs/farmer (90% of pig farmers), 2/3 is supplied by large indoor operations like those in the U.S. They have even built hog ‘hotel’ farms in China! I’ve never seen anything like that in the US.

Also, you all discussed that one of the control piglets in the study died due to lack of colostrum intake and wondered why. Unlike humans, antibodies do not cross the placenta in pigs (it’s too thick! 6 layers). Piglets are therefore born agammaglobulinemic and get all of their antibodies (IgG, IgA and IgM) from their mother’s colostrum. Without colostrum, they will usually die of infection.

Lastly, there was discussion as to why SADS-CoV may “extinguish itself out” after persisting for some time in the herd. During outbreaks like this, the herd veterinarian will work closely with the farmer/manager to implement strict quarantine and culling protocols. Additionally, infected sows that are kept around will develop immunity to the virus so that in her subsequent litter, those piglets will be better protected because the milk will contain antibodies against the virus. Milk IgA antibodies specifically play a major role in the protection of suckling piglets against enteric coronaviruses (such as PEDV, shameless plug J ).

All-in-all, this paper is another example why veterinary virology is so important! Not only to protect our food supply, but to improve animal welfare and prevent the zoonotic transmission of viruses.

I hope this helps clear a few things up!

p.s. For TWiV listeners, make sure to check out “Immune”! J

Stephanie N. Langel, Ph.D.

Postdoctoral Associate

Dr. Sallie Permar’s Laboratory

Duke Human Vaccine Institute

Anthony writes:

Good artists borrow, great artists steal  

Pablo Picasso

In Jersey anything’s legal as long as you don’t get caught.

Bob Dylan

# # #

You mentioned in one of the David Quammen episodes using the title Viruses Are Us.  Toys ‘R Us used to aggressively protect their name. How that will proceed with the bankruptcy, I don’t know.  No matter. Use The Viruses That Are Us — conflating Pogo.

It struck me that you could start with perhaps a Liberty Science Center feature on the viruses that have found a place in the human genome.  Maybe there could be a TWiVtacular recorded there on the topic? If the topic resonates, a book could follow. And many more would learn of TWiV.

Johnye writes:

Did Rich share the pictures he took? He photographed our “state of the art vaccine” refrigerator, maybe the incubator and sterilizer too and a stadiometer where you can compare your height against some greats: bald eagle, Justice Ruth Bader Ginsberg, Dr. Seuss, Chewbacca, emperor penguin and more!

I appreciate, and proselytize, the work you and your distinguished co-hosts are so passionately committed to and make engaging, enjoyable and educational (although more frequently I feel out of my depth with many of the laboratory methods, names of genes and their products, and the mechanisms of action. It’s harder to visualize what is going on.)  But back to proselytizing…I tell every medical student and resident who spends time in our office about TWiV and The MicrobeTV (is TMTV available for use) line up of shows. I also suggest the online lectures you and Brianne Barker post; nothing like clear, well organized lectures and teachers.

Look forward to Sunday’s podcast. It’s like the Sunday Times arriving at the door: something comforting, entertaining and thought provoking.

Wishes of good health, strength and warmer weather.



A little more than 10 C, overcast and light showers  

PS: Check the April 2019, Infectious Diseases in Children

Jerry writes:

Here is the list of vaccine bills going around the country:

There are 5 Vaccine Bills as of 2019 currently in debates they are

S.Res. 165: A resolution recognizing the importance of vaccinations and immunizations in the United States.

By Tammy Duckworth.

H.R. 1973: Vaccine Access Improvement Act of 2019

By Brian Higgins

S. 570: Flu Vaccine Act

by Ed Markey

H.R. 1371: Flu Vaccine Act

By Rosa DeLauro


H.Res. 179: Recognizing the importance of vaccinations and immunizations in the United States.

By Adam Schiff.

These Bills are on the Federal Level.

Here are all the states that have done their vaccine debates so far as of 2019.

Here are all the states that have done their vaccine debates so far as of 2019.

Jerry writes:

Dear Twiv,

A Texas Politician goes after Peter Hotez in the Vaccine Debates.

I remember Peter Hotez from the Twiv Special on Rachel  he got dragged again in the Vaccine debates that is happening nationwide at a state capital

Vaccine advocate Dr. Peter Hotez is accustomed to verbal attacks from anti-vaxxers, but on Tuesday the abuse came from an unexpected source: a Texas legislator.

In response to a Hotez tweet that the latest increase in vaccine exemptions in Texas shows its children have been “placed in harm’s way for the financial gain of special and outside interest groups,” Rep. Jonathan Stickland, R-Bedford, let loose.

“You are bought and paid for by the biggest special interest in politics,”

tweeted Stickland. “Do our state a favor and mind your own business. Parental rights mean more to us than your self enriching ‘science.'”

When Hotez replied that he doesn’t take a dime from the vaccine industry and that as a Texas pediatrician-scientist who develops neglected disease vaccines for the world’s poorest people, it is “most certainly my business,” Stickland dug in even deeper.

“Make the case for your sorcery to consumers on your own dime,” tweeted Stickland. “Like every other business. Quit using the heavy hand of government to make your business profitable through mandates and immunity. It’s disgusting.”

Dirk writes:

Riddle: How do you name a virus that is isolated from a fecal swab from a bat:

a BAtASS virus J

Thanks for the great podcast,

Dirk Jochmans (University Leuven, Belgium)

Lance writes:

Dear Vincent & team,

I don’t know if I can really be called a listener any more – as I don’t get time to listen nearly as much as I would like to these days! I am enjoying Immune very much.

Here is a BBC radio program on science publishing that I am sure you will find interesting, as will many TWiX listeners:



Dr Lance Turtle

Wellcome clinical career development fellow

Senior clinical lecturer/honorary consultant in infectious diseases

Institute of Infection and Global Health

University of Liverpool

Erik writes:

Hi TWiV Team,

It’s been a while since I’ve written in, but I have a couple of listener picks that I’d like to pass along. I think the listeners with enjoy both, but one of them is entirely, and shamefully, self-serving.

The first pick is a new podcast that Boston’s NPR news station, WBUR, is putting out called ‘Infectious’. It chronicles the history and present day anti-vax movement. So far I’ve only heard the first episode, but it was really good. It gave a history of the practice of variolation followed by vaccination with cowpox, and how the practices were received by a superstitious and alarmist public. The ‘Infectious’ episodes fall under a podcast called Endless Thread.

The second pick is my art website that I recently launched…like I said, self-serving. But I think the TWiV listeners will enjoy it nonetheless because my art is all virus-themed. I’ve loved painting images of viruses for years, and I finally decided to put all of my paintings in one place. The website is (that’s dot co, not dot com, because the latter domain was already taken).

Let me know what you think! 🙂

Keep up the spectacular work!