Frank writes:

This is Frank from Shickshinny PA. Why are we not using antisera from recovered patients with SARS-CoV2 to treat those newly infected or seriously ill? It seems this might reduce the viral load and give their immune system the time to catch up, seroconvert, and clear the virus. 



Frank DiPino Jr., PhD

Professor and Chair

Department of Biology

Misericordia University

Ed Niles writes:


I listened to the first part of TWIV today through the passive transfer comments.  It was claimed that passive transfer was first used for Lassa in 1968. Smallpox docs shouldn’t be shortchanged in this regard.  VIG was used a decade earlier. I went to a meeting in 2009 where several smallpox docs talked about their experiences trying a host of putative antipox drugs and the impact on their patients.  One had tears recalling the impact of treating sick patients with untested and unproven drugs. I understand the urge to try something but there are limits.

VIG is(was) prepared by two companies under contract from the US government, from pooled serum taken from vaccinees, mostly military at this point.  We have 100,000 doses in the stockpile. However, 25 doses have been used in some attempts to clear vaccination complications. This article will provide some background for the practicalities of preparing and using CIG, if we get to that.  It helped remind me of what we were thinking about 15 years ago. It seems like a life time.

On another note, pooled mAbs have proven to be effective against pox viruses in animal models.  Unfortunately, this is an expensive way to go. You can ask Merchlinsky if you have any interest in exploring this in greater detail.

Attached is a nice article that Rico published in 2006 that summarizes the prep and use of VIG over the decades.  He correctly refers to a handful of reported anecdotal applications of VIG against smallpox. I don’t know what true controlled studies have been done at this point.  By 2011, there were none. Even with the compassionate uses of VIG, ST246 and cidofovir it was never clear which if any of them had a positive effect. In each case, the patient cleared and survived.  Controlled studies are hard to come by.

So, I am not a big fan of VIG and if anyone wants an antibody approach to SARS COV 2 they may as well go directly to Mabs and do the right set of studies.  Of course, this will take time. Alternatively, if you have no other tools in the toolbox, maybe a convalescent serum study is warranted. Any volunteers?

Keep the faith!


PS  It has been nice to be reminded of Rico.  He was a wonderful guy.

I guess there is a chance that we will get the answer about passive transfer.  I hope that they try it early on in the infection , soon after the onset of symptoms and don’t wait until a late stage when the virus load is probably reduced and less important in the pathology.

Are there good numbers on the time course of virus accumulation and onset of symptoms and fate of the infected individual?  Someone must have done this in China if not in Italy or here. It would be informative to see the relation of virus load and pathology.  It would be best to see infectious virus rather than PCR.


PS  Looks like IIG predated VIG by several decades

Dan writes:

Hello TWIV,

       I am a mailman in MN. I had a couple questions/issues with the USPS saying “there is no evidence of covid19 transmission by mail”.

First, has there been a study on this (transmission via mail carriers) or are they just saying that because of the life of covid on paper and cardboard surfaces is relatively short?

Second, what about the fact that we touch every single mailbox every day? They are made from plastic or steel, where the surface life of covid has been shown to be days, and 99% of people are touching those boxes within 12 hours of me delivering to them.

These concerns are exasperated (exacerbated) by the fact that in my station of 40+ people we have 2 jugs of sanitizer, but workstations and trucks are not and have not been disinfected once since in my time here. We have not been given any cleaning materials or instructions on sanitizing stations or trucks.

On top of that me and 3 others at my station have significant others that are nurses, we are very concerned about being a vector and spreading covid throughout the city.

Thank you,


Melissa writes:

Hi everybody, 

thank you for a great podcast! I have followed your updates these last weeks about SARS- CoV-2. You`re doing a great thing, giving scientific, fact based knowledge and information as to where everybody can find good and reliable articles and updates. 

I am a Norwegian masters student, now working from home and social distancing myself , as so many others also do, in order to try and get this virus spread under control. I just reacted to your special episode having a medical student with you, and you mentioned herd immunity and it being the “method” Great  Britain and Norway are using against this virus. It is not, here in Norway we have all of schools and kindergarden and universities shut down for almost two weeks now and it will continue to be shut down for still some time. Also stores are closing earlier and all official social arrangement etc are cancelled. Most restaurants are closed. Everybody are encouraged to stay home, social distancing and so on. So we are doing what many other countries are doing here in Europe. And as you guys are now doing in the US. Number today in Norway for infected people are 2566 in total, new infectious the last 24 h are 196. Total deaths 11. 

Now, Great Britain was executing the herd immunity in the beginning, but then cancelled that, and started doing the same measures as we and other countries are using. Sweden on the other hand, have not closed schools and everything is open as usual, so I guess they go for the herd immunity strategy. We`ll see how that goes. 

Anyway, keep up the good work!

Just wanted to inform you of how things are here if you were curious. 

Take care,


Joep writes:

Dear all,

As a fresh general practitioner (age 32) in The Hague, Holland, I’m currently working in a bizarre world.

Two weeks ago the daily practise has changed dramatically, as for the entire world.

We work in shifts to spread risk of infection and two out of the eleven GP’s have been sick with Corona (1 tested positive, the other was denied testing due to low resources for testing). The daily practise is fairly easy going, with no patients coming in and a lot of reassuring phone calls. We only see high urgent care patients at our practise and are therefore not that busy during the day.

All the patients with COVID symptoms are ‘phone’ triaged by a GP and if necessary sent to a specially developed COVID part of the hospital where patients are seen by a GP with BPM and if necessary seen by a specialist. 

The measures taken by the government are getting stricter every day, trying to avoid a total lockdown. I can only hope that the way we handle things will have a good effect in the near future. The next few weeks will be very important to see if these measures are enough. The shifts are getting tougher every day, not just for us but certainly for all the specialists and nurses in the hospitals. In certain hospitals, specialists are asked to work on the ward, supervised by internists or intensivists.

On 22th of March I did an evening ‘Corona’ shift, where I visited the very sick at home. 50% (3 out of 6, a fairly easy shift) were highly suspected for Corona. I saw one very ill patient with an oxygenation of 44% (!). The man (age 75) had a light cough during a weeks time, no fever and his situation deteriorated over night. Medical history: hypertension and hypothyroidism. He is currently submitted at the ICU, intubated in prone position with a bilateral pneumoniae and treated with chloroquine. His wife who was not sick the 22th, has been admitted to the hospital yesterday. Both of them are COVID-19 positive. 

The reason I contact you, besides giving you an insight in our situation, is an article of JAMA ‘Detection of SARS-CoV 2 in Different Types of Clinical Specimen’ (link below) that shows low sensitivity for nasal swabs (low numbers)  and pharygneal swabs (bit more numbers). Can you explain me what the contribution is of a test with such low sensitvity? There is lot of discussion going on here about testing medical staff and the low resources that we have. As a GP, I am not that comfortable with statistics and would be very glad with your interpretations of the article. 

If you told me two months ago I would be contacting you bunch of intelligent beings, I wouldn’t have believed you. But your podcasts are a clear and trustworthy channel of information for me, in times where a lot of (mis)information is spread. 

Thanks a bunch for all your effort and time spent for a lot of people around the world. 

Yours sincerely,

Joep ter Haar

The paper:

Assuming all 205 patients were infected, the pharyngeal swab was only 32% positive.  My gripe is that the data does not convince me that all were infected. More studies needed.  Note live virus in feces. 

Rithu writes:

I am Rithu, a Virology student and an avid follower of TWiV since 2015. I would like to gain some expert insights on the SARS CoV-2 phylogeny 

( ) if possible.

Thank you


Emma writes:


I was struck by the percentage of positive tests in New Jersey (86% by Is this right, or some reporting error? 

If it is right, given that the national average is so much lower, does this imply that the actual numbers are much much higher in New Jersey, more so than elsewhere? And why does New Jersey seem to have so many fewer tests per case than other states?


Emma from Highland Park, NJ 

Svetlana writes:

Dear Professor Racaniello,

I recently came across your Virology lectures online, and have a question I wanted to ask scientific expert in this field, regarding the possibility of using acidified Sodium Chlorite (Chlorine Dioxide) to combat viruses such as Covid-19 as well as many others. I found a podcast on where you and your colleagues answered someone’s question regarding Chlorine Dioxide gas as a disinfectant against viruses, and it sounded like the first reaction is to assume that it’s the same thing as Chlorine, however they are two different chemical formulas. Common household bleach (NaClO) destroys pathogens through chlorination. Chlorine dioxide (ClO2) kills pathogens through the process of oxidation, there is a big difference.

Chlorine and chlorine dioxide are both oxidising agents (electron receivers). However, chlorine has the capacity to take in two electrons, whereas chlorine dioxide can absorb five. This means that, mole for mole, ClO2 is 2.6 times more effective than chlorine. If equal, if not greater importance is the fact that chlorine dioxide will not react with many organic compounds, and as a result ClO2 does not produce environmentally dangerous chlorinated organics. Why is CIO2 Different to Chlorine? | Chlorine Dioxide | Scotmas

It seems that a lot of experts in the scientific community ( maybe because they are not specifically Chemists) automatically make that assumption, therefore assuming that heavily diluted Chlorine Dioxide is dangerous for human consumption or the environment, but as you can see they are not the same thing. In fact here is a scientific study that tests the toxicity levels of Chlorine Dioxide Solution and finds it safe at the highest dose they tested which was 40ppm Efficacy and Safety Evaluation of a Chlorine Dioxide Solution. – PubMed – NCBI

Given the current crises the whole world is facing and a lot of testimonies online about using Chlorine Dioxide solution to treat many viruses and diseases, it would be a very important and potentially life saving discovery, to scientifically show whether or not Chlorine Dioxide Solution can kill this and other viruses in humans, just like it does in drinking water (which it is currently approved for by EPA and FDA, as well as for processing food)

I also found this scientific article on Chlorine Dioxide for Coronavirus treatment

(PDF) Chlorine Dioxide for Coronavirus: a revolutionary, simple and effective approach

Thank you very much,


Julia writes:

Hi guys,

I love your show!

I have an answer for one of your questions..

You asked why South Korea could ramp up testing while others haven’t and I don’t think the answer is entirely political. My reason for this I work on COVID19 testing for our state government laboratory in South Australia (SA Pathology). As far as I am aware we have tested the most per capita of any region in the world (17,000 tests for 1.7million population) and as an insider in this lab I can tell you the micro conditions that have allowed this to happen. We use in-house developed multiplex PCR, not commercial kits. Our scientist over many decades have developed testing and figured out how to combine assays with different probes to test as many targets as possible. Because it is in-house, the tests can be changed very quickly with only probe and primer sequences information needed and a quick QC process. Tests can be added and removed while maintaining workflow. We use separate liquid handlers, extractors and cyclers so if there are problems at any step we can use other machines or manually fix pipetting errors. We look at raw amplification curves to double check the software calls and use curve information to troubleshoot. Commercial kits hide raw data. Some of our commercial kit tests (used for other purposes in our lab) perform all steps on one platform and a failure at any point aborts the assay. The processes are hidden so we cannot retrieve any part and have no option but to repeat the assay from the very start.

My point is that our lab scientists’ contributions over many decades, dedication to find the best adaptable work flow, ability to troubleshoot and in-depth understanding of the processes going on within the machines and PCR chemistry and raw data makes for a very good system to deal with emerging viruses. We have grown a system that takes very well trained people to do the work but is more flexible at times like these than commercial platform assays. We can also source consumables and chemicals from multiple manufacturers so avoid shortages. We manufacture our mixes (away from testing) and QC each batch so adding a new test fits into this aspect of work flow.

The political part of our performance in my view (through my face shield) has been our federal and state governments giving us a lot of money to ramp up what we already perform.

I know you ask for questions but I thought I would share my perspective from the inside.


(Medical Scientist, SA Pathology)

Erion writes:

Hello team TWiV,

This is Erion, who is originally from South Korea, and I am “just a PhD student” in the Netherlands studying viruses.

First, thanks a lot for all the extensive and also frequent updates on COVID-19 situation. Since the lab has been closed here, I had a whole week to go through the corona edition of TWiV that I missed since January. It was really interesting, especially to hear different perspectives on COVID-19 including the clinical aspects. I really appreciate that you are trying to share all the knowledge and information like this. Big thumbs up!

From the last episode (593), I heard you got some questions about why Korea is dealing with the situation better than others. There’s of course not just one simple answer for this. Initially, I wanted to answer that question by myself, but then I conveniently found this article appeared on the Guardian that nicely summarized the situation in Korea, so I want to share it with you.

I know you probably get tons of links these days, so if I again summarize some points from this article regarding why Korea is handling the situation better:

1) Korean government was ready to mobilize based on the experience with SARS epidemic 2003

2) Korean CDC and biotech companies reacted fast to develop detection kits which later allowed up to 20,000 tests per day

3) Immediate testing of asymptomatic people was done from the beginning of the outbreak

4) People embraced rather intrusive measures (e.g., publicly informing citizens of known cases within 100 meters of where they are)

Now Korea is screening all the people arriving at the airports, both Koreans and all other internationals.

It is funny (of course not in a humorous way) that just a couple of weeks ago, I was the one who was worrying about my family and friends in Korea, and now my parents want to send me facemasks. Yet, many people still don’t seem to realize how serious is the situation or they simply decided to ignore social distancing.

Hope many more people are listening to TWiV while staying at home, and we can really flatten the curve soon.

Stay safe and healthy!

Best regards,


Alec writes:

Hello Vincent and All

Thanks again for all you do in keeping us informed during these interesting time to say the least. Just a comment about South Korea and how they seem to have been able to control the pandemic and the comparisons made in their approach. I did some work with South Korean hospitals when I worked in Asia and the Middle East and can tell you that they have an excellent healthcare system. It is a universal, well funded health care system, with open access to all its citizens. One point to remember though South Korea, like Japan and a couple of other Asian countries, is a homogenous country (even more so than China which has numerous distinct regional dialects). This may not be politically correct, but is often a lot easier to push directives like mandatory testing through in a homogenous society than a multi cultural one for various reasons. Although SK may be a democracy it has a very rigid social structure and deviation is frowned upon. What you may not be aware of is that when the government in South Korea put the country on a pandemic alert all the foreign workers were quarantined for 2 weeks (not tested) and sent home. There were 10,000 Thai workers who were sent home and some have since tested positive for Covid 19 (they were also supposed to be quarantined on return but not all were). This pandemic will not only test healthcare systems in most countries and how they react to it. Like everything else we should be cautious before drawing blanket comparisons between how countries respond as we aren’t always comparing apples to apples.

Once again thank you for all you do, and just wanted to tell you that I have totally given up on reading twitter, as I write this someone just posted something about how you can get the virus from gas pumps and was re tweeted 3000 times!

Thank you again 


Scott writes:

Dear Vincent et al,

In the discussions of the immune response to coronaviruses on Twiv I haven’t heard any mention of the role of mucosal antibodies. The vaccination strategies that are in the pipeline sound like they aim to induce neutralising antibodies in the blood, but surely IgA in the lung and gut mucosa would play an important part in blocking infection. What does our existing understanding of immunity to other respiratory pathogens tell us?

To provide a brief snapshot of how things are here in Australia –

Australia is faring much better than some other countries, but the situation here is starting to escalate. As of today (the 24th of March) we have about 1,800 confirmed cases across the country, with 7 deaths. Australia moved early to develop PCR assays, and the authorities took the outbreak in China very seriously. Travellers returning from Wuhan in early February were quarantined on an offshore island, and similar steps were taken with passengers returning from the Diamond Princess cruise ship in Japan. These measures seemed to help to keep the epidemic at bay at first, but we now seem to be moving into a period where the government is faltering and losing its grip on the situation. According to the Australian Dept of Health website, about 150,000 tests have been conducted so far on our population of 25 million, but up until now the criteria for testing have been fairly restrictive. This has meant that only people with a history of recent travel, contact with a confirmed case, or unexplained pneumonia have qualified for testing. We now have community spread happening in most states. Apparently the criteria for testing are about to be broadened now that travel has been severely restricted. The Australian economy is crumbling rapidly, with schools and all ‘non-essential’ businesses closed in the two most populous states of New South Wales and Victoria. This includes bars, restaurants, cafes etc. There is still a great deal of confusion about which other businesses will be allowed to keep operating.

I live in the small island state of Tasmania, which has a population of about 500,000 and a healthcare system that is strained at the best of times. We also have a large retiree population and the highest rates of smoking in Australia. Our state government effectively closed our borders last weekend, bringing in a policy of mandatory 14 day self-quarantine for all ‘non-essential’ travellers. At the time that decision was made we only had 7 confirmed cases in the state. In the last few days that has risen to 28, but so far every case has been associated with travel and there is no evidence of community spread yet. Despite this, pubs, gyms and restaurants have all been closed, and some private schools have moved to providing lessons online. Public schools are still open. Our state’s tourism-dependent economy has been completely trashed overnight. The way I see it, the next few weeks will be the critical period where we find out if all these measures have been enough. I just hope that the health authorities will now broaden the testing criteria and embark on an aggressive testing campaign. I work in a lab that develops vaccines for both viral and bacterial pathogens of farmed fish and I have been watching the situation unfold with increasing frustration. To me it’s obvious that we need to be testing more broadly and I wish that there was something I could do to help. There is still some sense that test kits are being rationed to a certain extent, and knowing that I have enough extraction kits and RT-PCR reagents sitting in the lab freezer to perform about 1,000 assays is driving me crazy. All I need are the primers!



Research Microbiologist, Tasmania

Bob writes:

Is there something questionable about chloroquine phosphate now that someone has died?

Michael writes:

In response to people’s questions about Korea, here is my partial translation of a Korean news article titled, “Korean 220,000 vs Japan 8,000… what was the secret behind the coronavirus testing in Korea?” (  (Note: I’m a computer engineer at University of New Mexico, so I’m heavily utilizing a dictionary to translate a lot of medical terms here. Feel free to update some of the words which may not be technically accurate.)

————- (start of translation)

South Korea is being praised around the world for its coronavirus testing. Currently, tests are being done at 18 public health research centers at both city and provincial level, and at 95 testing centers for civilians. As of March 10th, we are averaging about 17,000 tests a day.

The death rate is also the lowest among countries. It’s at about 0.7%. It’s higher than seasonal flu, which is 0.1%, but it’s smaller than MERS at 30% and SARS at 10%.

So, how is South Korea able to test so many, so quickly?  Why is it receiving praises? We are receiving a lot of questions here in South Korea.

The experts in South Korea point to the change in government policies when MERS hit in 2015 and took away 38 lives. The policy had changed to favor expedited process to release newly created viral testing kits to the public, and it also allowed for a quicker implementation of IT technologies to respond to an epidemic.


The Korean CDC has been preparing for a new epidemic after MERS.

The Korean CDC had created the “Center for Infectious Disease Analysis,” which housed the following:

Division of infectious disease diagnostics

Division of micro-organism (germs)

Division of virology

Division of mediator analysis

Division of high-risk pathogen analysis

It had created a center for infectious diseases and related work.

And also, in January of 2019, South Korea had implemented a policy to expedite the approval to use of new diagnostic reagents, in case when there’s no immediately available diagnostic reagents in the country. It allows for a thoroughly evaluated reagent to be approved for usage for a certain period. After such changes in organization and with its approval processes, it had created a basis to respond quickly to any spread of infectious disease.

Such measures had created a field for biotech venture companies to take active roles. There are two major parts to SARS-2 testing: molecular and antibody. The molecular level diagnostics is the more accurate one. Molecular diagnosis is a method in which the quarantine authority collects samples, extracts nucleic acids, and finally conducts genetic tests. It usually takes about 6 hours and you also need specialized facilities and equipments to do this.

To respond quickly, however, the antibody diagnosis can be effective. In the case of the antibody diagnostic kit, the primary infection can be determined in 10 minutes through bodily fluids in the field. Several domestic bio companies are also focusing on producing and manufacturing antibody diagnostic kits.

On February 27th, the Korean FDA has given emergency approval to the testing kits made by SeeGene, SolGent, SD Biosensor, and Kogene Biotech, and others. SeeGene has been flooded with orders from EU and 30 other countries for SARS-2 testing kits, for example.

A CEO of a biotech company belonging to the Dae-deok-dan-ji Group has said that, “It used to take about a year to release an antibody diagnostic kit, but now, thanks to the expedited approval process, we can release an antibody diagnosis kit within about a month and a half. It’s not a full, formal approval, but it allows us to bring test kits quickly out into the field.”


RT-PCR equipment deployed in hospitals across the country also played a major role in rapid diagnosis. After the H1N1 flu pandemic, RT-PCR equipment was installed in local health centers, including hospitals across the country.

At the same time, genomic data such as SARS-2 sequence was released through WHO, and speed of diagnosis of confirmed patients was accelerated. A comparison target was created that can determine whether or not a new virus is present without comparing it to other viruses. Hospitals and public health centers across the country are accelerating the speed of diagnosis by using existing equipment without procuring new equipments.

“A molecular diagnosis is an extremely sensitive test, so the accuracy can suffer and the risk can increase if the lab or the facility is not properly fitted,” said an expert in life sciences. “The PCR equipments installed at the local public health centers have increased the speed of such testings after the H1N1 flu epidemic.”


Software industry association representatives came together to create a COVID-19 Incident Response Team, and created a comprehensive situation map ( 

The companies that formed the alliance front include Korea’s spatial information and communication, cloud service company Gaon-I, Wisenut, which provided AI chatbots, and IT security company Eastsoft. The COVID-19 Comprehensive Situation Map’ service has achieved 100 million views so far.

The COVID-19 Comprehensive Situation Map is a location-based service provided on the basis of the GIS engine called Intramap created by Korea Spatial Information and Communication. It provides information such as clinics, schools, Shincheonji facilities, and AI chatbots, as well as the traced path of confirmed patients.

Gaon-I provided cloud server technology, and Eastsoft increased the convenience by placing the status map at the top of the search. Wisenut provided comprehensive information through AI chatbots. Korea Land Information Corporation (LX) paid a portion of the cost of the cloud service.

With such services, as soon as a patient was confirmed, his or her travel path was traced by epidemiologic investigator, and then shared with the public in a matter of few days.

(more paragraphs about the drive-thru)

————- (end of translation)

Thanks for your program, and may we come out as a more humble nation that strives to serve the humanity better!

Warm regards,


Daniel writes:

[ad: attached article displays a neurological problem that sometimes strikes older physicists, causing them to blather authoritatively on subjects about which they haven’t a fucking clue.]

Dear Vincent and TWiV hosts,

I am an undergraduate student and an avid listener of TWiV, TWiM, and Immune whenever I get the chance (usually on the walk and bus to or from school, which I miss dearly!). Thank you for your consistent coverage and invaluable perspective on the unfolding pandemic, although I am not fully caught up on all episodes. Kind of surreal how things have changed since I was walking to the bus stop listening to TWiV 582 at the beginning of the semester…  

My mom sent me this “analysis” today as a forward from a friend of hers, who claims to have received it from his friend who is a physicist and “… specializes in data collection, analysis, and interpretation…” (so, every scientist, ever!??). The author of this document, as you can see, is apparently Dr. Volker Hoffmann from Germany. A couple of red flags struck me at first glance, including: no mention of his institutional or organizational affiliations, no mention of references throughout except two big data hub sources at the bottom (only one of which seems reliable – worldometers does not report it’s sources of data and runs tons of ads), and being a physicist (lol).

I would be curious to hear your impressions of this document because the author makes some valid points:

e.g. #4, 7: the more testing, the more positive results. Obviously positive correlations will appear with frequencing of testing and positive results.

The author also makes some persuasive points, but leaves many statements unsupported and/or without reference. However, I don’t want to outright dismiss what is stated based entirely on “it is not cited” unless it is obviously wrong. The author also makes five giant, leaping conclusions at the end. Of the “conclusions” I can only agree with #3 without robust supporting evidence. How would the author explain #4 in the context of what has happened to the people and healthcare system in Italy, which has been expressed to us through the many harrowing anecdotes from front-line healthcare professionals there? #5 is revolting, with that background in mind.

As members of the academic community, do you feel this person has acted irresponsibly through the distribution of this document (I believe intended to be read and by non-academic journal reading people?).  

Since you are the experts, I will leave it to your discretion to discuss in whole or in selected parts if you wish. Thank you for this and for your inspiring work.


Daniel Major (He, Him)


Bachelor of Science

Mount Royal University

Nina writes:

Hi Vincent and friends,

From the epicenter of the US Covid outbreak, Seattle, I am writing you under sunny skies and 60F. This is a short-lived spring window before the rain is supposed to return later today, 3/23, for the rest of the week. That weather change will makes staying inside much easier compared to when the sun is enticing one to leave the house. I’ve spent the last 2 weeks mainly at home because my company has a mandatory work from home policy unless working in the laboratory to process clinical diagnostic samples and because of trying to stay in my social cohort.

One of the perks of being home/ inside more has been to pick up Twiv! I was an avid listener in graduate school (while doing tedious repetitive experiments lonely in the lab) and you even read out one of my letters back then. Wooo! I really appreciate your work and information broadcast on the topic. I’m amazed how your team of experts addresses all the questions and topics that I have including questions about secondary infection outcome and building immunity in the population while being socially cohorted. 

In Twiv 593 the question about understanding the immune response to Covid came up with the idea if you would be able to stratify population of responders and non-responders to the virus. I wanted to share a link to the official announcement of my company called Adaptive Biotechnologies. We are working open source on understanding the immune system response to Covid:

A snippet from the announcement is below:

“To generate immune response data, Adaptive will open enrollment in April to collect de-identified blood samples, using a LabCorp-enabled mobile phlebotomy service, from individuals diagnosed with or recovered from COVID-19 in a virtual clinical trial managed by Covance. Immune cell receptors from these blood samples will be sequenced using Illumina platform technology and mapped to SARS-CoV-2-specific antigens that will have been confirmed by Adaptive’s proprietary immune medicine platform to induce an immune response. The immune response signature found from the initial discovery work and the initial set of samples will be uploaded to the open data access portal. Leveraging Microsoft’s hyperscale machine learning capabilities and the Azure cloud platform, the accuracy of the immune response signature will be continuously improved and updated online in real time as more trial samples are sequenced from the study”

Thanks for doing what you are doing. Informing the public is ever more important in our current time.



Ryan writes:

Dear Twivologists,

Love the show and the caliber of guests you’ve been able to bring on! Very cool that you find time to engage with us the listeners as well. Question for you about the 593 episode, where you answered a question about treating Covid-19 symptoms with Tylenol.

Are you concerned that acetaminophen might attenuate the patient’s fever, to the detriment of the immune response? A fever isn’t free, and certainly some people don’t have the cardiovascular or metabolic foundation to handle the extra say 500-1000 daily calorie burn of a strong fever, especially when the energy might have to come from fat oxidation pathways that they aren’t accustomed to using. But when a patient has the requisite physicality, why not let the fever rip, especially in an early Covid-19 case when the lungs aren’t compromised? Subject to monitoring and observation, of course.

In a situation where the immune system might be our best weapon, it might be prudent for nonhospitalized patients to avoid introducing any new OTC meds (NSAIDs and Acetaminophen both). We discover more about the immune system every year, but the picture looks pretty clear that it is adapted to do particularly well in hyperthermic temperatures.

For example, here’s a Nat Rev Immunol paper from 2015 that covers a variety of mechanisms where by a fever appears immune-protective. Fever and the thermal regulation of immunity: the immune system feels the heat

And yes, Daniel does need to buy a bigger boat, as do the rest of you. 

Take care of yourselves!


Anonymous writes:

Hi Twivers!

I’ve written in before (long time listener) and I appreciate your coverage of COVID19. As with everyone else, I am writing in to discuss it. 

As this refers to some privacy issues, if you do mention this on the show, could you drop a bit of the quasi identifiers? I want to share my info, but I don’t want to risk my family’s privacy.

My sister works in retail in the Detroit area of Michigan and had a really bad bout of an unknown virus back in late February. She had a fever, chills, and was coughing so hard she pulled a muscle in her side. She’s 27 and has some digestive underlying conditions. I listened to your episode from Sunday (3/22) and immediately locked onto the diarrhea symptom. She had this, but we’d dismissed it as part of IBS. I spoke with her today and she also had the early symptom of funny/bad taste of normal foods. She went to the doctors twice, got two negative flu tests, but never got a SARS-CoV-2 test because we didn’t have any in MI, and we weren’t even thinking to test at this point.

I’m writing in the hopes that this information could be helpful to anyone you know trying to model. And also important for not only MI cases, but Ontario as well. The store she works at has a lot of Canadian traffic too. She and a coworker were both sick, neither of them had travelled anywhere in recent history, meaning SE MI either had community spread in February or someone happened to bring it into her workplace after returning from somewhere that did. Unfortunately, since no one was testing, she did not quarantine herself, nor did my parents who live with her. 

My 60+ year old mother came down with this”mystery virus” as well, but is faring better than my sister (no diarrhea and no almost running to the ER), but again no testing was done, so I can’t confirm my sister’s case. However, she

Thank you for all that you do (COVID and otherwise), 


Kit writes:


I listened to episode 593 last night, very informative, and inspired lots of thinking here – thanks for your great work.

Might SARS-CoV-2 be damaged by a kitchen microwave?

Obviously, mask supplies are straining. Depending on the dielectric properties of the virus, it might heat-up quickly. There’s some precedent from the CDC:

The microwaves produced by a “home-type” microwave oven (2.45 GHz) completely inactivate bacterial cultures, mycobacteria, viruses, and G. stearothermophilus spores within 60 seconds to 5 minutes depending on the challenge organism.

Based on a few quick tests here, the metal parts on N95 masks can handle at least 60 seconds without getting so hot as to damage the mask.

We’d love to fund a study on this to find out, but I have no idea where to start. Do you have any advice on who to contact etc?

Thanks for your time!

Jean-Francois writes:

Hi TWiV,

I’ve started listening a couple weeks ago, just after Professor Racaniello did a presentation at Google. I’m enthralled by having access to this level of great information and analysis.


In ep. 593 you talked about influenza trends that were possibly linked to social distancing and other covid-19 measures. I would love to hear what you have to say about the trends we can see in the Weekly Influenza Surveillance Report from the CDC

More Background: 

I started looking at it from a couple weeks back thinking that this would show trends regardless of the availability of SARS-CoV-2 tests, but I fear I’m reading it with too much of a positive spin, since I’m worried and would love for someone like you to say what they think of the trends we see in those reports.




Neil writes:

[ad: wants to know how hospital architecture helps infection control, and whether this pandemic will lead to changes in it.]


I am an architect, and have been appreciating the show since things got crazy in Wuhan. I have even gone back and listened to some older shows since I’ve been cooped up. As someone in a socially constructed field that loves rigid categories (open a building code), I am really fascinated by the way viruses confound our neat little categories. The discussions about mitoviruses, plasmids, and early life in particular really left me with a lot to think about.    

What I would love to hear more about is about design and transmission and protection. Two aspects – design of medical buildings to prevent transmission and unexpected transmission via building systems. 

At the moment, I would love to know more about the use of mechanical, plumbing, and security systems for infection control in medical facilities. This might be second nature to clinicians, but it’s always nice to talk about the basics especially as we build improvised hospitals. I saw an improvised ward in a parking garage. Those are supposed to have high air flow because of cars’ combustion gases, but no filtration or conditioning. Is that really a good idea? I know some hospital architects who might be able to put you in touch with the right people. 

More long term, the aerosol transmission of SARS via floor drains and bathrooms was interesting because bathroom floor drains are rare in American and European homes, but common elsewhere. On the other hand, the paper notes that ventilation was poor in these bathrooms and a lot of US apartments have bathroom fans that only operate when in use, but feed into shared stacks so might spread contamination if the exhaust is not strong enough to draw to the exterior. Though I am not a mechanical or plumbing engineer, my job includes coordination – imagining potential problems and making sure the specialists work them out. I would love to know of more research on this topic. 

The revolutions in indoor plumbing between 1850 and 1940 in the US had huge impacts on society, and their aesthetics heavily influenced the development of architectural modernism  Similarly, after 9/11 building codes were changed to address fire protection and exit issues. I am curious if anyone is thinking through the application of what we learn from this pandemic. 

Thank you!


Ellen writes:

Hello all! 

My boyfriend and I visited Denver & Vail, Co in early January. When we returned we developed a fever for several days and a cough that lasted over 4 weeks. We both went to our Doctors and were negative for the flu. We are in our mid thirties and generally healthy, so whatever virus we had didn’t completely knock us out, but it was unlike any kind of virus either of us has ever had. Of course I know there is no way to know if we actually had the Coronavirus at this point, seeing how it was months ago, but do you all think it is possible that Corona was circulating well before we detected it here in the states?


P.S. I am only curious, and will most certainly continue to follow the guidance of local, state, and federal health officials . 

Thank you so much!


Lafayette, LA

Felix writes:


I like your podcast, but I still haven’t learned your names… so hi all!

Okay, I have 2 different questions. Let’s go.

1) Kinds of vaccines. What ways do we currently have of making vaccines? What are the differences between them? Which of these are being considered/explored for the campaign against COVID-19?

2) Immunity. How does immunity ultimately work? Why is it that some vaccines have an expiration date on the immune system (like tuberculosis)? Does immunity wind down as time passes? Is ultimate immunity impossible, or is it possible to be vaccinated and otherwise healthy and still get the measles? Does it depend on the disease itself?


I guess I had more than two questions, huh.

Oh, and stay safe. Thank you for making your podcast even during this pandemic. It’s much appreciated and much needed. Thank you so much.

– Félix

Betsy writes:

Thank you for this podcast. I’d like to submit a question for your consideration:

Why isn’t take-out food a high concern for spread? It would seem that this is a weak link in our prevention chain in cities like NYC because  a) restaurant workers are least able to stop work if they’re not feeling well because they don’t have sick leave and need the income to pay bills, b) restaurants are not equipped to do temperature checks on workers c) spread from asymptomatic patients is now seen as a big contributor to the spread in other countries. 

Thanks to all of you.

Stay healthy,


Gary writes:

Thanks to you all for all the clear information, and for the fun we get to share with you in exploring all things viral.  

An interesting hypothesis was published about a week ago that the production of ACE2 receptors may be up-regulated in response to ACE inhibitors and receptor blockers.  Assuming the virus binds to a site distinct from that bound by blockers and inhibitors, the up-regulation should logically result in a greater rate and number of COVID-19 cellular entries, and reasonably – more severe disease.  As people with cardiovascular and renal disease, and diabetes are commonly on ACE inhibitors or blockers, the idea is that those co-morbidities result in the taking of ACE inhibitors and blockers and that the meds, not the diseases result in the increased risk of severe disease. What are your thoughts?  (Ref.: James H. Diaz, MD, Journal of Travel Medicine, March 18. 2020.)

Shweta writes:

Hello TWIV, 

I am a PhD candidate at Erasmus Medical center at Rotterdam. I listen to the podcast sometimes and lectures from Prof vincent taught me virology. I work on Epstein Barr viral antigens as targets for immunotherapy for Nasopharynx cancer. Due to the current outbreak i am obviously out of the lab and working from home. But my first love is working in the lab. I am trying hard to think of all the people who are in a worse situation than me but the stress is getting to me. I am currently working on some objectives that i made given the situation like improving my informatics skills but a large part of my project is on hold. 

I thought it would be nice of you guys to discuss in your podcast how could PhD students or people who are at home now handle this situation ? 

Any tips/reaffirmations i could use to prevent being labsick will be appreciated

stay safe 


Tumor Immunology lab 

Erasmus MC Rotterdam 

Anonymous writes:

Dear TWiV, 

Thank you for your amazing coverage of the real science and medicine associated with the current pandemic. It’s been nice to hear a level and real perspective. I learned about your podcast in February from a friend on Facebook and have been listening ever since. 

I have a question about the apparent change in severity of disease we are seeing between China and Italy, for example, and between disease reports from the west coast of the US and the east. From what we are hearing, it seems like there has been a shift in the virulence of the disease, and that China, Washington state and California have experienced a disease targeting more older and compromised people, but Italy and places like New York are seeing a much scarier, more severe disease that is targeting younger and older people. I can’t find any speculation to this effect on the web, but have you heard anything to this effect?  

Thanks for what you’re doing,