Chia-Wei writes:

Hello TWIVer,

I want to make a quick comments on Kathy’s questions on PPE.  She mentioned there are huge Chinese characters in front of the doc’s PPE and wondering what they are.  Those are just doctors/nurses’s names. Since PPE needs to be stripped after each use, it is the easiest way to identify the individual. 

When I was working in West Africa for Ebola trials, we did the same thing, writing their last name with marker on their PPE.  On top of that, we write the time they enter the isolation unit. So we can track how many hours they worked inside the unit.

I also saw pictures from Wuhan with dozens of health care workers slept on the floor or foldable chairs in their PPE.  This is an extremely poor practice to use the PPE. It might be a combination of staff shortage and supply shortage. Health Care workers are simply not protected at that point.

Thank you for the great episodes.  I am always excited every Monday morning to listen to new ones on my one hour commute.  Thank you!


Liping writes:

Dear This Week in Virology,

Thank you for answering my questions on COVID19, two more if you don’t mind:

  1. There are dozens of videos showing men in their prime fainting, dropping to the ground face down. Some of the videos might be fake, sure, but based on the fact that  videos are taken all over the country, it is likely to be a genuine clinical manifestation of this disease. I am guessing the fainting is due to lack of oxygen? The pathology paper published on Lancet only dissected tissue from the lung, heart and kidney. Is it possible that this virus can attack the central nerve system as well?
  2.  I am an automation engineer, and I spent a lot of time thinking about dynamic balance. This disease looks like an overshot of the immune system to my untrained eye. Can we train our immune system such that it can hit that goldilocks spot to all the invading pathogens, even the emerging ones? Much like I would train a machine to balance itself under various conditions.

Just try to chip in as an engineer:) 

I have been reading the latest Lancet papers on the Wuhan Coronavirus. and I’d like to pick your brain on the following questions:

  1. Patients still test positive after discharging and still shed virus, does that indicate that this virus is similar to Hepatitis B virus such that we can be chronically infected by it, whether or not it manifest itself depend on how strong our immune system are?
  2. The have find virus in the faecal martial and much like SARS in HK, there has been people be infected via the bathroom pipeline transmission route. Are their any know good practices to minimize the aerosol in the bathroom system?

Thank you for taking the time. Fingers crossed that my questions get picked for the next podcast!

Best Regards,

Bai Liping

Nathan writes:

Dear Esteemed TWIV hosts:

I look forward to another podcast on all things about coronaviruses. 

Query: I’ve seen news stories on SARSCoV2 reinfection and I’m puzzled.

How do they measure this reinfection?  I don’t believe antibody tests available and I thought that measuring IgM was the way to determine if one had an active infection. If you could discuss this question and surrounding issues, I would be most appreciative.

Also, kudos for the discussion and show notes about fecal oral transmission of SARS.  This week has brought a flurry of news stories about alternative modes of transmission of SARSCoV2.

It’s sunny and cold in Chapel Hill -2C (28F) with about an inch of fresh snow in our backyard.

Thanks for all you do.



Blaine writes:

Dear TWIV,

I have a question about the development of a vaccine for the new SARS-COV-2 coronavirus. It is my understanding that at least one vaccine had been developed by the Chinese for the original SARS virus (please correct me if I am wrong… thanks). 

If this is the case, then would it not be simple to reformulate a new vaccine with antigens from the old virus? The process would presumably be similar to what is done annually with influenza vaccines and not require new clinical trials, but simply would just require the antigen change up and manufacturing.

If this is not the case, then what have we been doing for the last 17 or so years since SARS emerged in Hong Kong? It was only a matter of time before other coronaviruses would emerge and cause a panic. (Don’t forget MERS coronavirus has also popped up). Why would we not have a vaccine ready to go for this inevitable event?

Thanks for your responses.

All the best,


Fort McMurray, Alberta, Canada

Nancy writes:

Dear Dr Racaniello and  team, 

I listen avidly to TWIP mainly. Have done for years with great pleasure and enthusiasm.  It is the one most immediately accessible to the ignorant! I have recently started with TWIV again , – from the beginning.  Dickson and Vince – what great discussions!

I am hearing of reports that people who have recovered from the virus and been released are turning up with positive test results.  What do you make of this? If it is real do you know what is going on? Apparently these folks are not sick at all. 

Here in the Laurentians of Quebec it is -6C and somewhat overcast. We are awaiting a mighty wallop of snow starting this afternoon. Last of the season possibly?

with warm regards 


Ian writes:

Smoking must make coronavirus worse

The above quote in the last episode reminds me of this fun study.

“Methamphetamine reduces human influenza A virus replication.”

Free bonus Plaque assays!

(don’t read abstract)

Abstract in part “Herein, we investigated the effects of meth on influenza A virus replication in human lung epithelial A549 cells. The cells were exposed to meth and infected with human influenza A/WSN/33 (H1N1) virus. The viral progenies were titrated by plaque assays, and the expression of viral proteins and cellular proteins involved in interferon responses was examined by Western blotting and immunofluorescence staining. We report the first evidence that meth significantly reduces, rather than increases, virus propagation and the susceptibility to influenza infection in the human lung epithelial cell line, consistent with a decrease in viral protein synthesis.”

Ian Stirling, from a still chilly Fife. Scotland.

(I suggest a flu jab is probably better for you)

Robert writes:

hello twiv.

i have a friend that is working as a nurse on the diamond princess as part of the commission corps help effort. my question is what do you make of the fact that the virus seems to effect people that get it so differently with some people not even knowing they have it and some people having their entire family killed off. do you think that the vast majority of it is just people that have some underlying issues, or is it possible there are two different strains, is it genetic, or in some contexts are there opportunistic diseases that also spread along side the virus?

thank you and have a great day.


David writes:


Enjoy your show. Would be interested to learn your thoughts on antibody mediated cell entry and coronaviruses, particularly as it might impact the development of vaccines and synthetic hyperimmune globulin as a drug for SARS-COV-2.

There are several reports of ADE occurring in coronavirus infection, e.g.

Making a synthetic hyperimmune globulin would be straightforward given modern biotech. Make an scFv phagemid library displaying the B cell Ig repertoire of COVID-19 survivors, pan for high affinity spike protein binders, reformat as IgGs and test for in vitro neutralizing activity. Are there ways that we might select for antiviral mAbs and avoid ADE mAbs? Also relevant to vaccine development. Would not want a vaccine to make the virus more virulent by giving it the ability to invade B cells!

Also a biology question. Are the other human coronaviruses close enough to SARS-COV-2 close enough that there may be some antibody cross reactivity? Could this be a situation like dengue where exposure to one strain of the virus may increase the disease severity of another strain?

Thank you,

David J States MD PhD

Ann Arbor, Michigan

Gerry writes:


I’m Jerry the a pest control from Los Angeles have been following TWIV since 2012 or so.     

Your podcast has been valuable for our vector control efforts.    

We work with California Office of Emergency Services in Hanta control, and local Equine E, and West Nile.  

I am currently both concerned and fascinated with the 2019 corona virus.    I have been watching your educational videos to determine the

possible mechanisms to limit viral load in this disease.

I told my wife in early January that I thought Arbidol, a protease inhibitor or possibly interferon would be of  some efficacy and we were surprised to see that there were some subsequent studies launched using these treatments.

My questions are other antivirals such as fusion inhibitors, integrase inhibitors.   I’m getting in to areas I don’t have much knowledge though. Other than ACE-2 what other mechanisms can these virus be inhibited?

Also,  the fact that children are not really susceptible is interesting and a blessing.     Do you think this is just the fact that kids are able to recover quickly or perhaps there is a mechanism that we can exploit.  

I was under the impression that children have a smaller  immune system library in there white blood cells. Do you think a difference in apoptosis or a lack of something possibly be the reason they are not effected?

I would like to see some effective tools to limit deaths until a vaccine can be developed.

Thank you 


Sergey writes:

I was wondering if you could maybe discuss on your show whether air pollution in China might have an impact on the severity of symptoms of COVID-19 and possibly explain why the outbreak is much more severe there compared to parts of the world where the air is less polluted.

Many thanks for your highly informative show!  Keep up the great work!


Jordan writes:

Dear TWiV, 

I’ve been listening intently to your coronavirus podcasts since the Wuhan outbreak gained traction in the news. While I think the reporting and info on the initial couple you did was appropriate and informative I was really disappointed in how you are handling more recently. I know that TWiV does not ‘traffic in conspiracies’ but I feel like your desire to remain non-conspiratorial or something of that nature is preventing you from discussing real possibilities of what’s happening on the ground. I don’t think a lot of the questions coming out of this virus outbreak are conspiracies as much as they’re a highly possible scenarios given past evidence. Please see notes below: 

-ISSUE 1: In TWiV 586, I was shocked that you made little/no mention of China under reporting the death toll during this episode. I was waiting the whole episode for you to discuss the very high possibility that China was way under reporting numbers. However, if anything you complimented China on being so open and upfront after the initial attempt to cover it up.      Not even questioning the validity of the numbers. Meanwhile reports are sneaking out of China that there are body bags piling up, crematoriums running 24-7 and what was possibly leaked death toll numbers onto China’s version of Twitter. Those possibly leaked numbers were massively higher than the government issued values and were corrected down almost immediately. It was plainly obvious to anyone who knows about China’s locked down media history that this virus outbreak is another example of how China will control outgoing media with an iron fist. And yet all of you highly intelligent scientists just glazed over all of this evidence and track record of this country. And then today (2/13), China releases updated numbers that jump the toll up much higher. I doubt we can even trust these numbers at this point and they are likely much lower than the reality on the ground. Are we really going to believe that they quarantined 100 million people when at the time less than 500 people had died? This is much bigger than the world media knows. Saying that isn’t a conspiracy–it’s critical thinking and analysis based on historical evidence. 

-ISSUE 2A: The TWiV team has also fought strongly against ANY possibility that the BSL4 facility has anything to do with this. Claiming that the Chinese people are competent (which I believe they are) and this wouldn’t happen there.     Yet, I feel asking questions about the BSL4 connection has little to do with the fact that it’s a Chinese facility. It has more to do with the fact that the first known cases didn’t start in the market (from what we know currently) and this outbreak happened in one of a minuscule number of cities in the world that has a facility that works on extremely dangerous viruses. I would expect the same reaction if this happened in a United States BSL 4 faculty. 

-ISSUE 2B: In keeping with this, you were stating this coronavirus isn’t man-made and it is 96% bat virus. Wouldn’t these virologists in any research facility START with a known virus and then use techniques to ‘modify’ the virus.

 I would not expect scientists to be creating viruses out of nothing. They would be taking know viruses and doing work on them. Which is possibly what happened here. Please read this article below and respond to your thoughts on it. I’d like to hear from real and respected scientists about the information in this. I’m sure someone will research this source and find out that they ‘lean right’ or something and totally discredit it (even though it has nothing to do with politics), but I implore you to at least examine the info in this. I’d like to hear your thoughts on the possibility of all of this.

Appreciate all you do for virology and thanks in advance for answering any of these questions! 

Thank you, 


Glenn writes:

Asal writes:

Hi TWiV- PodV-1, 

As always, thank you for the great podcasts about viruses and as one of your listeners has put it in a letter, listening to TWiV keeps me young! 

I am sharing an article published in The New Yorker magazine on Feb. 15, 20. It would be great if you got a chance to read it and share your thoughts about it!



P.S., I addressed you in this letter to rhyme with the ICTV’s naming of the newly emerged virus! Here it is unfolded a bit: TWiV-podcast in Virology- number 1 in the world!

David writes:

Hi All at Twiv

As a Clinical Microbiologist (think cross between ID Physician, Laboratory Microbiologist and Infection Control) in the UK dealing with the on going fallout of coronavirus I wonder if you have come across any information to answer the following questions:

  1. How many people are dying from coronavirus and how many with coronavirus? We know that many of those who supposedly die from viruses actually have secondary infections with other organisms such as S. pneumonia, H. influenza and S. aureus, or die from other causes whilst also coincidentally having the virus. This would skew data about death specifically from coronavirus pneumonia. If bacteria are a secondary problem here is it the “normal suspects”?
  2. Is anyone doing work to look at any collateral damage to health from patients either getting less than optimal care for other medical problems whilst clinical staff are fixating on the risk of coronavirus, or were other areas of the healthcare systems are being distracted by coronavirus? So far in the UK we have apparently done over 3000 tests and found 9 cases…

By the way we’re being battered by Storm Dennis here at the moment; it’s cold and wet and quite a bit of flooding… all good conditions for forcing everyone inside to share their viruses with their families… 

Love the podcast and amazed at your sustained enthusiasm, great job!


James writes:

Dear Vincent & the rest of the super TWIV ‘Viro’ gang.

I have been a faithful listener to TWIV for over 4 years now & enjoy your show immensely. 

Although I work in a completely unrelated field, I have long held a soft spot for both Virology & Bacteriology. 

Most likely because as twelve year old boy, when asked during an interview for a top notch British Grammar School, what career I wanted to pursue? I somehow spontaneously responded, “I’m going to be a Bacteriologist!’ 

I have absolutely no idea why I said that at the time, but the interviewer must have been impressed & to my parents delight, I secured a place in one of the country’s finest Grammar schools. Albeit somewhat dubiously.

Not surprisingly, I now work in marketing… so go figure! 🙂

But getting back on topic – my question for TWIV revolves around the ‘Corona cruise from hell’ & the pandemic proportion of cases on the ‘Diamond Princess”, the cruise boat stuck in port, off Japan – with 544 positive corona cases to date out of 3,500 total passengers & crew.

I’m guessing this represents the highest concentration of cases in the world currently – maybe ever recorded outside of a hospital? And on the face of it, appears to have been a huge error or miscalculation.

On the TV news here in the UK, a Virology PHD lecturer from UCL (who I won’t name) has stated a number of times, that decision to quarantine the ship was indeed the correct thing to do. 

But, it is just not currently understood what has gone wrong on the boat & that the causes behind the rapid & widespread increase of positives needs to be investigated so we can understand what went wrong.

HOWEVER – I believe that two weeks ago, Vincent made a comment on TWIV, questioning the very rationale of the decision to hold everyone onboard, citing that this policy could result in a mass concentration of infected folk:  quod erat demonstrandum! (I told you it was a good school)

So why in your opinion was this decision taken to quarantine people in such close confinement when the risks of mass infection were, so very apparent to the experts? What should happen next to avoid this occurring again & what are the wider lessons & implications for future viral outbreaks?

Thanks again to everyone for such a great show!

All the best,


Jim writes:

Thank you for your wonderful podcast, which I just discovered when searching for more information on coronavirus.  I’ve been interested in viruses for years and read a few books on the subject. Your podcast is approachable and informative for the lay person. 

Here are my questions.

News reports that two young doctors, aged 28 and 35 have died in China from the NCov2019 coronavirus. This fact runs counter to the prevailing wisdom that this virus is most dangerous for the old and immune compromised. With regards to viral load, is it possible these fatalities have more to do with the amount of exposure these doctors would’ve received seeing multiple patients during the early epidemic?  

Also there are several reports that patients seemingly on the mend have rapidly declined, and in some cases died. Is this aspect of morbidity a trait common in other novel zoonotic viruses that have recently crossed the species barrier?

Finally it was comforting to hear virus experts express that they are not currently personally worried regarding the current outbreak.  More expert perspective is appreciated regarding relative risk. Certainly let us know if your opinions change.

Thank you,


Johan writes:

Hi Twiv,

I follow your podcast regularly. Since nowadays sequencing and peptide synthesis is extremely cheap, I want to see if free and open source vaccine design can become a thing. Was wondering if you may know other open source enthusiasts who are well versed in immunology that may want to contribute to something like that. The vaccine design is basically a list of peptides that should elicit an immune response in persons of a matching HLA type. Open source means that nobody can patent the chosen sequences of peptides and anyone is free to make it (assuming they follow applicable laws obviously).

I started a page with some of my preliminary work on this already. I am not sure whether to paste the link since that may get blocked but I created a page for it on github-dot-com   /feraliscatus/VxAfee