Dana writes:

Good Morning Dr. Griffin – 

I heard that an Optum Clinic is now using a short Q tip for anterior nasal swab, rather than the longer deeper nasal swab for Covid-19 testing. 

Certainly would produce less coughing and gagging, but does it work? Is the data published?

Thank you,


Dana Lustbader MD, FAAHPM

Chief, Dept.of Palliative Medicine

ProHEALTH, an OPTUM Company

Professor of Medicine 

Hofstra Northwell School of Medicine

Tom writes:

I looked at an info sheet on ventilators, and I think I answered my own question. I thought I would ask those that know more anyway just in case: could a ventilator be modified to handle multiple patients? Obviously it’s less than ideal if mechanically possible, but for the lower percentage chance end of the triage curve, maybe it’s a chance that to previously be there.

Great podcast. 69 degrees and sunny. Very nice

John writes:


I really enjoyed episode 593 and wanted to know if SARS-CoV-2 can be transmitted by breathing in cigarette/vape smoke from another person infected with COVID19. Transmissibility in this form would be particularly concerning in urban environments, since cigarette/vape smoke can easily travel more than 200 feet. 


John from Portland, Oregon

Daniel writes:

Really concerned that pretty soon district nursing staff and primary care doctors will be expected to go into homes of COVID patients and palliate them at home.  Currently Welsh guidance within the healthboard state a standard surgical mask Type IIR, plastic apron and disposable gloves constitute appropriate PPE.   I feel that guidance I have read from around the world relating to COVID is that this is not safe PPE especially if staff working to set up syringe drivers etc at bedside in a patient’s home.  Are there any good peer reviewed resources you have links to that I can use to back my stance as public health are admitting to just using guidance from pandemic flu preparation. 

Any useful peer reviewed materials to back my stand would be gratefully received.  I am in contact with our local MP and Welsh Assembly member who are interested in any resources I can provide. 

Thanks for your continued sensible approach to the developing science here, your podcast has been required listening for me throughout this period (when I get spare moment!)

Keep up the good work

Dr Dan Weaver


Doug writes:

Two questions.

Do these drop in cleaners such as the one sold by SoClean [https://www.soclean.com/uk]  clean coronavirus off the CPAP equipment?

If these machines kill the coronavirus could they be used to clean and therefore reuse the N 95 mask?



Salem, Illinois

John writes:

Thanks for all the help.

The question on many minds concerns the apparent Chinese success in limitation of COVID 2 to a small portion of a large susceptible population. Since the chinese are weeks ahead of the rest of the world, we should be interested in how control outside of the initial Wuhan outbreak region is being maintained. We may assume that the relaxation of control measures has been carefully calculated to allow social and commercial activity while limiting spread. What does the TWiv group know about the specifics of current Chinese policy?

John Terry MD

Scott writes:

I live in HK and have been keeping a close eye on the daily updates about the now around 400 covid positive people reported by our local CDC who are all analyzed as to how they might have been exposed to the virus.

One thing i find curious is that our city is not locked down and all the shops and restaurants are still open, but no one has been randomly infected out and about the city.  None of the tens of thousands of cashiers at 7/11s and supermarkets, who must meet hundreds of people each day, have contracted the disease.  

Do you think this is because of the brief period of contact, or the fact that they wear masks and/or probably are being very careful not to touch their face being in such an exposed position?

The local outbreaks have all been from family members or else social events where people are not wearing masks and have been together for hours indoors.  The amount of virus one is exposed to must be very important because of the lack of random infections.


Katherine writes:

Hello Twiv,

Today I was talking to my kid about this coronavirus. She raised a question I don’t know, so I decided to write to you on her behalf. The question is what is the first virus or disease? Do you have a clue of it?

Thank you,


Aishwarya writes:


I am a first time listener- after this coronavirus pandemic hit but so far love the podcast! I am a pediatric resident and planning on being an allergist/immunologist. It was interesting to note that hospitals in NYC are using large doses of Vitamin C which seems to help. What is the evidence for this? I know that there has been some controversy in terms of Vitamin C preventing and treating colds. How does this fit into virology?



Sophia writes:

sorry, I really don’t want to crowd your email but I do have some questions that maybe other people have as well. Here they are:

1. blood donations: this virus doesn’t transfer through blood so I am assuming it’s safe to receive blood from potential carriers. However, the virus might get to your heart or liver (so it would be in your blood). Sorry, I am confused now

2. organ donation: a 42-year old, died yesterday from pulmonary embolism. He had tested negative upon coming to hospital. He was an organ donor. He was tested again before starting the donation and was found SARS-CoV-2 positive. Donation was cancelled. Was that to protect medical personnel or the recipient? I am assuming he wasn’t donating his lungs….

3. can you get infected by a corpse? I keep seeing people in protective gear carrying coffins. Isn’t that a waste of protective gear? It’s not Ebola, right?

4. is virus on your hair a big deal? Medical staff keep complaining for lack of protective hair gear. You can just wash your hair, right?

5. what if I can’t wash my clothes. Can I spray them with alcohol instead? 

6. can you talk about viral load in saliva (for asymptomatic people)? bad time for meeting strangers nowdays I guess….

all the best


Ruth writes:

  1. I am curious about the issue of post-infection shedding of COVID19.  Since the diagnostic being used for this is PCR, is it possible that people are shedding pieces of RNA but not infectious virus?  Perhaps some culture studies would be helpful, or perhaps there are other methods to determine if infectious virus is present.
  2. I am concerned that the chatter about the chloroquines, and even azithromycin does not touch on drug-drug interactions.  Hydroxychloroquine has numerous significant drug-drug interactions, including QT prolongation (which can adversely interact with azithromycin, which also can prolong QT).  Non-prescribed use is a very bad idea. Besides QT prolongation, Hydroxychloroquine can increase hypoglycemia in diabetics on oral agents and increase beta blocker levels.

Ruth Greenblatt, MD

Professor of Clinical Pharmacy, Medicine, Epidemiology and Biostatistics

University of California, San Francisco

Justin writes:


this makes a NYT subscription worth it alone



Per writes:


I’m writing this from sunny Stockholm (10°C/50°F) the epicenter1 of the Coronavirus outbreak in Sweden. 

Our Public Health Agency has made many suggestions2 that differ from most other countries. For example they’ve decided to keep our pre- and elementary schools open. Part of their reasoning is:

We believe that it is not at present a meaningful measure to close all schools in Sweden. There are no scientific studies showing that such a measure would have any significant impact. Also, there is no data pointing to any major spread of covid-19 in schools anywhere in the world.3

Unfortunately they don’t provide any references, which is why I ask for you:

1/ Is it true that there’s no studies showing that closing schools would have a significant impact?

2/ Has there been no reports of major spread of covid-19 in schools?

I’m especially concerned about them stating that there’s “no major spread of covid-19 in schools“. Couldn’t the lack of reports be because children generally have milder symptoms? If they’re wrong it could become really bad, especially in Stockholm since many of our schools bring in children from all around the city.

What’s worse is that since most children have mild symptoms, they won’t be tested, since Sweden as of ~2 weeks ago have limited testing to health care workers, and seriously ill individuals due to lack of test kits.

Thank you for your helpful, and enjoyable discussions!



1 Sweden’s statistics: https://www.svt.se/datajournalistik/the-spread-of-the-coronavirus/

2 Our Public Health Agency makes suggestions that our government then generally follows.

3 Regrettably the statement is only available in Swedish – although there’s an English version, it significantly differs from the Swedish one.

Richard writes:

In TWIV 593 Rich advised the researcher with melancholy for the lab to exercise. My daughter advised me that her diversion from working at home is an entertaining choreographer in LA (Silverlake) that has an live Instagram dance class. He goes live 3 days a week and, in keeping true dance class form, takes the pain out of exercise. He makes it fun to overcome the inertia of “sheltering in place”!


Richard Schoenbaum, D.D.S.

See this Instagram photo by @thesweatspot: https://www.instagram.com/p/B-GcFXIpn7J/?utm_source=ig_web_button_share_sheet

Garrett writes:

So it’s clear we can’t yet test everybody. Right now the CDC priorities are to test hospitalized patients and symptomatic health care workers first and the symptomatic general public last.

This seems backwards to me. If there is no approved treatment for COVID-19 then knowing a hospitalized patient is positive doesn’t change how they’re treated and they’re already quarantined by being hospitalized. Not testing the symptomatic general public means we’re not testing the people who will go home and spread the disease because absent a positive test they will not voluntarily self quarantine. 

What am I missing?


MJ writes:

What do you make of the proposed relationship described by some of decreased olfaction and gustation (that is smell and taste functions)?

Has much of this suggestion filtered back to you?

I see practically nothing in what I might consider true Medical Literature, mostly only in various News Media sites as quasi-rumor.   One possible exception is https://www.news-medical.net/news/20200323/COVID19-patients-describe-a-loss-of-smell-and-taste.aspx

The business may perhaps be of some importance from my consideration, though by no means with anything more than speculation.

I know that olfaction receptors function to a good degree under the mechanism of 100s of differing G-Protein receptors.   

I also know that Respiratory Syncytial Virus has had some mechanism of lung injury in neonates through attack on G Protein receptors per the work of Ralph A. Tripp at the U. of Pittsburgh (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5774885/) certainly this known to you.    The agent CX3CL1 (Fractalkine) is important in this through adhesion molecule action as a modulator of inflammation.  

The same CX3CL1 also participates in chemoattractant function and is involved in the G-Protein elements of olfaction.

I have no idea of what this means whatsoever.   It may be a total coincidence and the G-Protein family is so broad and with so many different actions, classes (inhibitory or stimulatory of C-AMP and more) that I have no idea if the seeming coincidence might even be some look alike relation of differing systems sharing some common form and be absolute gibberish.

What I would be asking here is could Covid19 be working through some action at the CX3CL1 or a similar receptor to damage Human adult Respiratory Epithelium in a manner analogous to RSV and could that possibly underlie some alteration of smell and taste as well, that is, assuming that there is any association in reality at all?

Do you know if anybody is looking into CX3CL1 or any other molecular level action of Covid19?    Would they be interested in such a possible exploration or such a waste of time?

I am a retired Primary Care physician who is frustrated that there is nearly nothing I can find of the pathophysiology of SARS or MERS at the deep chemical level and obviously no real time for serious work to have been done on Covid19.   I clearly do not expect to have any answers and perhaps not even any really good question here. That is why I am asking you. I suspect that the whole here is a huge waste of time. On the other hand, if it might not be, could it hurt to ask you?

David writes:

There have been anecdotal reports of health care workers suffering usually severe courses of COVID19 and an excess of deaths among health care workers. Could this be due to route of infection? Community acquired disease is most likely to occur through people touching their face and seeding via a nasopharyngeal route. On the other hand, short range aerosol infection clearly occurred in SARS and is occurring in COVID19, and it seems plausible that health care workers treating coughing patients and performing procedures are more likely to be infected by direct aerosol seeding of the lung.

This is, of course, speculation. I wonder what evidence or animal models you virologists might bring to this discussion. It has tremendous practical importance in determining what type of PPE health care workers need, the bunny suits and N95 masks seen in China and Korea, versus the yellow paper smocks and surgical masks (droplet protection) seen in many US photos.

Thank you,


David J States MD PhD

Ann Arbor, Michigan

Andy writes:

Hi Twiv team, new listener over the past week but amazing show, I love your attention to detail and promotion of honest reporting of facts

I’m thinking of an anecdote you shared regarding SARS being transmitted by a poorly configured toilet system and aerosolized to infect an adjacent apartment building and wondering.  What would happen if you ran a PCR on New York City’s raw sewage right now? Could trending the RNA content potentially be used to gradually lift social distancing measures to “titrate” the transmission rate as to not overwhelm healthcare systems in specific regions?



Lachie writes:

Dear all at TWIV,

Greetings from Melbourne, Australia, where the weather is 27 degrees Celsius and those of us who garden are wishing for rain.

I am a train driver, have listened on and off for about four years. One of my comrades baked this cake for his daughter’s birthday this week, which of course was a family only celebration. I thought you might appreciate it! Her name is Eva C and she has turned 12 hence the EC-12 nomenclature.

On a more serious note, I work with multiple people, sharing locomotive cabs and mealrooms. I have been washing hands or sanitizing every chance I get, and trying to stay away from my comrades as much as possible. When I get home I disinfect the door handles as I go inside, take my uniform off in the laundry, immediately wash it, and walk naked to the shower (not a pretty sight). 

My wife is “covided” at home, and I do not want to bring virus in on my clothes. We have stopped visits to elderly parents and visits to or by grandchildren and friends. Can you suggest any further steps I can take to prevent bringing this plague home?

Thanks for all you do.


Matt writes:

I acknowledge that nasopharyngeal swabbing, properly done, can be quite uncomfortable.

That said, this powerful study of 8274 patients in Wuhan examines this issue in great detail and establishes in my mind that nasopharyngeal swabs are clearly the best way to go, chiefly because it reduces the risk of false negatives.

You can view its contents by clicking on the “.pdf preview” screen.


Matt, California

VJ writes:

My name is VJ, a fan of your podcast and a medical technologist from Thailand. Thank you all of you for organising this very useful podcast. 

In the situation of COVID-19 outbreak, as far as I concern, most countries deployed the 14-day self quarantine. I do agree that to cease the epidemic, this measure is not an option. I am writing this email seeking your comments about the duration of this quarantine. Is 14 days enough? 

As we know the symptoms of COVID-19 patients are ranging from nothing to severe pneumonia. If one has quarantined themselves for 14 days correctly , is there any possibilities that one still ongoing infected with SARS-CoV-2 and shredding the virus given that the infection cause no symptoms at all. Can you give the rationale of this self-quarantine.

Again, thanks for your time. 

Thank you, 


Ryan writes:

I hope all shows are aware of this. 

Although there was a TWIV 594 segment where a commenter talked about the death in Arizona where he and his spouse took Chloroquine Fish Tank Cleaner in the report this  article goes back 40 years earlier of a reported Chloroquine death back where a 2 year old child from Oklahoma died from Chloroquine poisoning. 

Warning do not get your medical advice from Del Bigtree. Del Bigtree on his youtube show made an announcement as if Chloroquine cures people of COVID-19 but that is not the case its a candidate for clinical testing along with Remdesvir and various COVID Vaccine Candidates. 


Bob writes:


No its not a cure for COVID-19. Del Bigtree should be removed from Youtube for making the claims. The FDA was still investigating Chloroquine for clinical tests. This person needs to be removed or else more people will get killed like the person in Arizona faced

Tommy writes:

Good morning,

I’ve been researching sterilizing N95 masks. I came across this article that may be informative.

The podcast is great. Have a wonderful day!


He sent: https://drive.google.com/open?id=1hsru_Tu8MPqtdAarkL697maLHFO1P6ag

Which is https://www.ncbi.nlm.nih.gov/pubmed/?term=19805391

David writes:

Dear All at Twiv

Listening to the Podcast during a quick break of Tea and Donuts kindly donated by the local supermarket.

Thought you might like to know that there is LOTS of information about how infection control works into the building of hospitals here in the UK. This is part of the remit of the Infection Control Teams (Clinical Microbiologists and Infection Control Nurses) amongst many other things. The only Doctors in the UK aware of this type of work are the Clinical Microbiologists

It would be impossible to break this down further but you might like to glance at the official documentation produced by the UK Government bodies some are called Health Technical Memoranda and others are Health Building Notes. These are the standards that UK hospitals have to be built against, and to which Architects have to comply. Back to Covid-19 clinical work…



Hope that is of interest and thank you for all of the great information you are tirelessly sharing, it’s so valuable to us on the ground in hospitals.

Best wishes


Consultant Clinical Microbiologist, UK

Frank writes:


My mother, who is over 70 years young works as a medical assistant for a urologist.  She lives alone on the first floor and I live on the second floor with my wife and child.  I have asked my mom to stay home for the time being and I would take care of her by paying her bills and purchasing any essentials that she needs.  My mother refuses to stay home and continues to work.  I have voiced my concern about her catching COVID-19 because of her age and me not wanting her to be sick.  What if she does contract COVID-19?  How do I protect myself and my family from contracting the virus from my mother?  We are in separate apartments, but I am concerned the particles from this virus are aerosol and may travel to my space and infect myself and my family.  What are the chances of that happening?  Also, I need to travel down a set of stairs to exit the house to the outside.  If my mother is quarantined in her apartment, do you think it’s safe to exit my apartment? 

Thank you again for your wonderful work!


Bill writes:

Hello Everyone, 

What are your thoughts on this? 


There’s no question their hearts are in the right place, but will these things work? Are they safe? Is it better than nothing? Im guessing the face shields work just fine, but I’m dubious about the respirators and swabs. 

Thank you, 


Neil writes:

In case anyone needs to convince people that social distancing is important…  

Harold Varmus makes a cameo appearance at the end. 

Stay healthy (it’s OK to write it) And never stop podcasting



Neil Parkin, Ph.D.

Data First Consulting, Inc

Rachael writes:

Dear Vincent and team,

Thanks for your informative podcast about viruses. I am completely ignorant on this topic and your podcast is helping me learn more.

My question is, in the uk there is a lot of talk about an antibodies test for Covid 19 to see if you have had it. My question is would such a test be useful in terms of knowing you won’t spread it to others, and how much immunity would having caught the disease confer on you from catching it again? Is this test useful or not and if so how? 

Kind regards, 


Diana writes:

Hi there lovely Twivvers 🙂

I rediscovered your podcast in these Coronavirus times. I appreciate your chattiness and your candid conversations. I also appreciate the way you connect with your listeners by reading some email, so I thought of giving you some insight on what’s happening in Portugal.

We had our first case on March 3rd, and our government declared state of emergency on March 18th, when we had 642 confirmed cases and 2 deaths. Today we have 2995 cases and 43 deaths. These might not be as impressive as our neighbour Spain, but we only have a population of 10 million.

Our health authority now recognizes that we have multiple active transmission chains, and today they changed the criteria for testing: until yesterday you would only get tested if you had symptoms AND a close contact with a positive case, from today on they’re relaxing the criteria and increasing tests, although the light symptoms in non-susceptible people will still go untested. Which makes sense, because at this point no one has enough testing capacity.

We’re doing RT-PCR tests, but I don’t know how many. Some news outlets say 1500, some say up to 9000 a day. But we already have drive-through testing sites and a field hospital in a Lisbon covered stadium. Yesterday a news from Spain said that the quick tests that they bought from China don’t work properly. (https://elpais.com/sociedad/2020-03-25/los-test-rapidos-de-coronavirus-comprados-en-china-no-funcionan.html, in Spanish)

Our government announced that they’ve bought 500 ventilators and my own municipality (Cascais) says they got 5 for our hospital. You can see all the municipality measures here: https://www.cascais.pt/covid-19-pandemic-cascais-city-council-measures.

From what I can see from my home windows and strolls in the neighbourhood with the kids, I think people are mostly staying home, although we still get photos circulating in social media with way too crowded places.

In my household we’re also worried about the looming economic crisis. Portugal has a fragile economy.

My questions for you:

1. For papers published in biorxiv and medrxiv, do you know a way to find in which journal they will be published? I’d like to read some of them after peer review.

2. You mentioned that China’s numbers come from the closed areas, so…basically Hubei, right? How do you know that? Until you said that I thought that their numbers were from the whole country…that means that we don’t have the numbers for the rest of China? Hmm.

Thank you so much for what you do.


Oh, I almost forgot some important reports: we have sunny weather (as we usually do), and 14ºC. We are low on toilet paper but I don’t get what’s the deal with it, most houses in Portugal have bidets


Diana Ribeiro

Pharmacist & Medical Writer

Topper writes:

I’ve heard a lot of questions about face masks providing personal protection, but not much discussion about the epidemiological consequence of wide spread face coverage. 

Given the importance of respiratory droplets and asymptotic infection in the spread of the disease, wouldn’t widespread face covering in public, even with cotton scarves, reduce the rate of spread? Not because uninfected individuals would be less likely to contract airborne material, but because many more infected individuals would have a physical (if porous) barrier in front of their respiratory system reducing exit velocity.

Or do I fundamentally misunderstand how respiratory droplets act as the the mechanism of spread?

Not a virologist or epidemiologist, but I do write  software for them.

Reno NV, 32 F/ 0 C, slightly snowing. All the snow is coming after the pandemic closed the ski resorts.


Petra writes:

Dear TWiV Crew,

Greetings from shelter-in-place in Millbrae, CA (just about 10 miles south from San Francisco), where it’s cloudy after overnight rain and 58F (13C). Thank you for your very informative podcast. I’ve been listening for years and also very much appreciate your coverage of the ongoing pandemic. 

This is my first time writing in and I hope my contribution would be helpful for you and your listeners. In ‘recent’ episode 592 (time seems to disappear into Covid-19 black hole in recent weeks), you were wondering if the mRNA technology has been proven to work. I’m an immunologist by training and currently work for the pharma giant Roche/Genentech. Roche in collaboration with German BioNTech, and others – mainly Moderna and CureVac – are testing something called personalized cancer vaccine based on the mRNA technology. As the name implies, this technology can be customized based on the mutations found in an individual’s tumor and the resulting mRNA is optimized by in-silico selecting peptides (produced from the mRNA) that are predicted to be the most immunogenic. These peptides are also selected to match well with that individual’s MHC antigens for best possible presentation to the immune system. This is still in relatively early stages of clinical development but clinical trials are indeed ongoing. I’m attaching a paper Letter to Nature from 2017 describing an early proof of concept for the personalized cancer vaccine and a review from Science 2018 discussing the underlying concepts and immunology. 

Additionally, below are links to the respective companies website showing rich pipelines in vaccines for infectious diseases as well as cancer. In terms of timing of clinical trials for the SARS-CoV2 vaccine being developed by Moderna, attached is a snapshot of an article in Endpoints News describing a potential way to accelerate the development.

Keep up the great work and thank you!

Petra Volna

Moderna:  https://www.modernatx.com/pipeline

CureVac:  https://www.curevac.com/our-pipeline

BioNTech: https://biontech.de/science/pipeline

Alan writes:

Dear TWiV,

I sent an e-mail to you a week ago (Mar 18) asking about the use of ozone to decontaminate closed places. My letter was not considered this week on your podcast.

Ozone is toxic to humans and is probably toxic to SARS-CoV-2. It should be good to decontaminate hospital rooms between patients or large spaces like auditoriums, restrooms, and gymnasiums between uses by large groups. I would like to know if any decontamination studies are being made using ozone. This is not a worse suggestion than using microwave ovens to decontaminate PPE and masks.

Here are some links to others suggesting the same: