Jerry writes:

First and foremost, thank all of you for the wonderful service and education you are providing all of us who are just things other than infection disease experts. I, like so many, am addicted to the knowledge, banter and caring you display. You have come to feel like extended family to me.

I have always been bothered by the lack of experimental correlation between testing and risk of transmission. I understand how contact tracing and other things can work as a proxy, but would love to see a direct experimental connection.

I came across this article, that might be able to fill in this gap. It claims to use subresolution microimaging and AI to be able to identify sars-cov-2 in ejecta from speaking or such. It’s eerie having these tools pull such detailed information in the blurs, but that is actually one of the things AI is quite good at

First, I was wondering if there was some way to first have the system locate what it thinks are virus, then contact transfer the droplets onto a divided replication surface. Then you could see if there is competent virus at the places the AI had called out. They may need to do more/different training to get the AI to match reliably.

If that were to confirm the detection method, you could add this to a testing experiment and see the direct correspondence from testing to competent virus in ejecta. For me, this would approach a gold standard for testing as a correlate of transmission.

I don’t see this as a basic testing method like they seem to suggest, but I do like their idea of looking for tools far outside the common set.



David writes:

Hi TWiV,

A lot of the controversy around WIV centers on their method for testing wild coronavirus spikes. There are two ways they do this: by putting the spike in a pseudovirus that’s very safe, and by making a chimeric coronavirus, which is controversial. Do you think the benefits of testing a wild spike in a WIV1 backbone outweigh the risks? Why not just use pseudoviruses? We can make humanized mice sick with a WIV1 chimera, but are we really sure we’re learning something about the virus that the spike came from? Or is this just so we can check the “in vivo” box on a publication?

From WIV’s released grants, the uproar is about the fact that they made pathogenic chimeras, but the benefit is that they revealed that there are coronavirus spikes in nature that we didn’t know about, and should be concerned about. The question is, could they have come to a similar conclusion with just pseudovirus assays?



Bob writes:

Wow!  After the thin gruel of journalistic “science”, I always look forward to TWIV episodes, but episode 802 was so meaty, I just finished my third time listening! I may need a long nap to digest  this!

One thing I wonder about… given the uncertainty around the reported case to actual case ratios, have there been any broad serological surveys to figure out how many people have antibodies one way or another? I am just an armchair epidemiologist, but some of the case multipliers I have seen would put us near 80% exposed via virus and/or vaccine and producing antibodies. That would put us just months from complete immunity. This does not mesh with everything that is happening, so I have to feel that we must be reporting cases more completely than we think.

Thanks for all you do. I always feel ahead of the game after listening to you, having noticed that whatever skepticism or doubts you have about the latest headlines you have start getting expressed in the media about two weeks later.


[802 was “Another epitope with Shane Crotty”]

Laurie writes:


I am a nurse in Bozeman, MT and I love your show and listen to Daniel and the gang weekly (almost). I really appreciate the education you are making available to all of us. 

We are giving more monoclonal infusions now more than ever in my town and that is 10 a day. My question is, in 3 months if these folks remain unvaccinated will they be “fresh meat” for another infection? Will there be a post monoclonal wave if they remain unvaccinated as many have stated? Are they without antibodies?  

This is a vaccine question. Some nurses are saying that since there are more and more infections of the vaccinated, that there is no reason to get a vaccine. My thought is with masking, social measures and vaccines we slow the spread and decrease the infection rate. If we allow it to keep spreading so much we are increasing the chance of mutation and slowing our get back to “new normal” way of life and work and play. And vaccines are safer than getting infected, possibly getting more seriously ill or having long covid.  Now,  some other concerns nurses have is that the vaccine used fetal cells in the research. Is that true? That is not an issue for me, but these are some of the road blocks. I listened to the show about young women and fertility concerns, so no question there.

Keep doing what you are doing. I know it is hard, I am burned out from this and we aren’t even overrun in my hospital, very busy, but not totally overrun. We will get thru it together and again I am thankful everyday for the education from your shows. 

One more question. So we have a communal break room where we eat lunch. Montana passed a law this year that forbids an employer to ask employees their vaccination status. I ask some coworkers and know about 20% in my ER are not vaccinated. I mask when changing and eat outside, but winter is coming and I will move inside, any thoughts?  

Thank you TWIV,

Laurie RN

Lori writes:

When I see a new TWIV on my podcast player, my heart leaps with a little “yippee”. I’m so appreciative for all you do.

I don’t know if someone has picked this as it’s been out a while: Project Hail Mary, by Andy Weir.  Science fiction is NOT my preferred genre, but I find Andy Weir’s science fiction to be more plausible than most, so I like it. The hero is a PhD-scorned-by-academia junior high science teacher. There is an alien. There is an organism, astrophage, threatening life throughout the universe. It’s great. The plot is not perfect, but there is some good science and engineering and it made me both laugh and cry. Apparently, they are making it into a movie starring Ryan Gosling, date not yet announced for release.

Thanks again,


Spokane, WA

Kevin writes:

Hello TWiV team,

I am writing from the heartland of Wisconsin, where it is a perfect 73 degrees Fahrenheit.  Due to this summer’s drought – particularly in the northern part of the state – some of the trees are already changing to some wonderful Fall colors.

This week I came across the website  It is a glorious website that has exhaustive and quite comprehensible content (for the novice ecologist) on – you guessed it – oak savannas.  Oak savannas are one of the most decimated ecosystems in the world, with many estimates stating that less than 0.02% of the original pre-settlement oak savannas exist today.  The linked website has pages describing oak savannas and the flora and fauna found there, how to restore and manage an oak savanna from start to finish, and a bit of encouragement on why we should care.  Looking at the pictures and setting out to find one last weekend, I think they are just beautiful and largely underappreciated landscapes.

In the spirit of microbiology, the site also happened to have been authored by the late Tom Brock and his wife Kathie.  In addition to his work in Yellowstone (most notably discovering Thermus aquaticus), Brock was an avid conservationist.  They spent much of their retirement restoring the oak savanna landscape at the Pleasant Valley Conservancy in Wisconsin, which is now a public State Natural Area.