Vincent, Rich, and Brianne discuss a study estimating the fraction of symptoms and severe disease after SARS- CoV-2 infection, cellular immune responses without seroconversion during interfamilial infections, and answer listener email.
Hosts: Vincent Racaniello, Rich Condit, and Brianne Barker
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Links for this episode
- Paul Offit interview (Human Vaccines Proj) 4:03
- SARS-CoV-2 vaccine graphic (Milken Institute) 7:48
- Probability of symptoms and severe COVID-19 (aRxiv) 29:44
- Cellular immune response without seroconversion (medRxiv) 10:09
- Image credit
- Letters read on TWiV 631 49:00
- Timestamps by Jolene. Thanks!
Intro music is by Ronald Jenkees
Send your virology questions and comments to twiv@microbe.tv
Interesting discussion of Tcell response. What about discussing the cd4 vs cd8 response to leprosy? Cd4 and you get wicked disease and cd8 you get mild disease. Maybe we need to do a cd4:cd8 ratio for covid?
Relating to the question about bike riding in the wake (slipstream) of another rider, there is a study done in the Netherlands relating to this. Here is the URL which contains links to the paper itself and a Q&A: http://www.urbanphysics.net/COVID19.html
Basically the paper is based on studies of droplet propagtion which were performed in a wind tunnel with some CFD simulations of the flow field around a moving person (walking/running).
The Q&A is of the most interest because it contains recommendations for distancing while walking/running/biking in the wake of another person.
Politics in virology.
There may never have been a better example in human history than the role a country’s politics and it’s political economic ideologies play in teh spread of an epidemic and a pandemic than what is going on in USAmerica right now.
A country’s political system should be an integral part of the modelling data used to project the spread of infectious disease.
It’s a sad and dangerous precedent being set by the Republicans and Capitalists that assumes science and politics do not affect each other.
.
More politics in virology.Politics active role in spreading SARScOV2
” Face Mask Exemption Cards and Flyers with DOJ Seal Are Not Real, Feds Say ”
https://www.newsweek.com/face-mask-exemption-cards-flyers-doj-seal-are-not-real-feds-say-1513275
A child asks, “Can Sars-Cov2 be spread through farts?”
Well, I was on the floor laughing. I love this podcast.
That was certainly a highlight! I listen to podcasts while I’m putting my children in bed and wait for them to fall asleep. I laughed out loud when this question was read and my 5yo was like: “why are you laughing, mommy? It’s sleepy time!” and I. Just. Couldn’t. Stop.
Having 3 boys, I can attest that they’re all about farts
—–slaughter house—-
Hi I today is my last day at work as (JUST) a food safety auditor at the biggest ovine slaughter house in New Zealand. We worked through SARS-CoV-2 luckily with no incident in the plant, even with the production halved, I believe if one of the worker was shedding, at least five or more would have been infected with reasons below:
– it’s a requirement to maintain positive air pressure in slaughter house.
– carcasses conveyed through chain in a straight line while workers line up to dress and gut the carcasses. Due to ergonomic reason the rotate to different positions every few minutes and very little space for them to move around due to moving hooks and knives so they get very close to each other.
– we started implementing mask and face shield but workers usually refuse as it’s too hot (very physical work)
– at the same time it is boring work so they have to chat with mates and it’s loud in the slaughter house due to machinery (conveying) so they have to yell into their friend’s ear.
– not sure about other slaughter house, the one I worked for the workers average age is like 50 yo.
– most people including (especially) the plant manager have zero knowledge about microbiology
I have a question though.. it was brought up before the entry point of the virus (eg. eyes, muscle, respiratory, or orally etc) could make huge pathological difference. Has there been any study on it? For any virus really, I would like to read more about it..
Fun fact, I was invited to apply for PhD in U of Florida Gainesville for microbiology, i did but didn’t get in.
Can I do a shout out too? To my manager Muriel Rusike and the technical team where have been amazing!!
New Zealand had been SARS-CoV-2 free for a bit but active cases have increased again as border selectively opens. I am from Malaysia originally I’m quite proud of how Malaysia is doing on their numbers..
You guys have been trying to avoid politic, I did too.. until I realized great leadership saves lives, Jacinda is amazing! Unfortunately US and Brazil are at the opposite end of that spectrum. In the case of US, the harm is not just limited to Americans, the world suffers for the wrong 2016 decision some people made.
Love you show thanks for the information you guys have been putting out.
I found some interesting material regarding Covid-19 conspiracy theories. (Open access). Fascinating reading, and maybe some help in disseminating good information.
https://escholarship.org/uc/item/0pq269hb
Conspiracy in the Time of Corona: Automatic detection of Covid-19 Conspiracy Theories in Social Media and the News
2020
Author(s): Shahsavari, ShadiHolur, PavanTangherlini, Timothy RRoychowdhury, Vwani
———————–
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233879
https://phys.org/news/2020-06-conspiracy-theories-emergeand-storylines-fall.html
June 26, 2020
How conspiracy theories emerge—and how their storylines fall apart
by Jessica Wolf, University of California, Los Angeles
———————-
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233879
An automated pipeline for the discovery of conspiracy and conspiracy theory narrative frameworks: Bridgegate, Pizzagate and storytelling on the web
Timothy R. Tangherlini ,
Shadi Shahsavari ,
Behnam Shahbazi ,
Ehsan Ebrahimzadeh,
Vwani Roychowdhury
PLOS
Published: June 16, 2020
https://doi.org/10.1371/journal.pone.0233879
The fart/fecal question is funny, but would have been more insightful if we could have expounded to the question “What is the risk of contracting covid-19 using public restrooms?”.
Don’t see the relative risk link Rich said he posted.
Thank you for a very interesting discussion! My question is about the word “seronegative”. Does this mean that a person has no detectable antibodies against any SARS-CoV-2 proteins, or does it simple mean that they don’t have detectable antibodies against the three SARS-CoV-2 specific antigens that have been identified to date (spike proteins and nucleoprotein)? It the answer is the former, please disregard what follows. However, if the answer is the ladder, this begs another question.
The significant proportion of people that have appeared to be exposed to SARS-CoV-2 but remain asymptomatic (or have mild symptoms) remind a lot of how vaccinated (or “immune”) people experience seasonal flu (no or mild symptoms). While I realize that specificity is a major priority at the moment (and thus the narrow focus on antibodies against SARS-CoV-2 spike proteins and nucleoprotein), it seems entirely possible that a subset of the population that have had prior exposure to other coronavirus might enjoy sufficient cross-reactive protection for the immune systems to be activated by, and rapidly respond to a nominal “socially distanced” dose of SARS-CoV-2 (as oppose to, for example, a more crushingly large intimate relations dose) exposure, and rapidly mount a cross-reactive “memory” response against the non-spike/nucleoprotein constituents of SARS-CoV-2 (and effectively neutralize the course of viral disease)? Given the speed with which a “memory” immune response can act as compared to a primary/de novo immune response, it might not be incredibly surprising if the immune systems in these lucky (and young) individuals might substantially clear the virus prior to the body mounting a robust antibody response against the novel SARS-CoV-2 nucleoprotein and spike proteins. As an ex-HIV virologist, I can recall the many iterations of the “HIV positive” assay before the field eventually moved to a more comprehensive Western format that screened for a pretty broad collection of known HIV proteins (I know this because our work over-expressing certain MoMLV proteins in E. coli had the antibodies in my and my lab mates’ serum lighting-up a somewhat concerning number of proteins in the “HIV” assay), Anyhow, I wanted to mention this point because I can’t recall any old/fast rules of viral immunology that specify that the immune system can only mount a “disease neutralizing” immune response by targeting proteins that we know to be unique to a specific virus (no matter how convenient that might be for the scientists that are fixated on developing sensitive and specific SARS-CoV-2 antibody assays- seriously, how often does nature ever to the “convenient” thing?). Anyhow I just wanted to raise an alternative hypothesis because it might provide an explanation for at least some of the “asymptomatic” exposures (and it should presumably be easier to look for then going down the whole T cell/CMI route). I’m also concerned that there might be an element of “scientists (and docs) are very good at not finding what they’re not looking for” at play here (and I just wanted to raise the above possibility in case we haven’t already looked). Thank you again for your excellent discussion!
The quantiferon test is a commercial 24h inf-gamma test for T cell responses against tuberculosis. Does types of tests do exist