Stephen writes:

Dear TWiV Team:

Like literally thousands before I would like to thank you all for the tireless work you do and publish.

In the latest TWiV #665 an important topic was almost brought up but not fully discussed.  That is, if one is in a Sars Cov 2 Vaccine trial, six months to a year into the trial ‘a’  [someone’s] vaccine is released. Should that person be allowed to know if they are in the Placebo part of their trial (by simply asking). This is a serious Bioethics issue that I know many would appreciate hearing the opinion from each of the TWiV regulars as well as Dr. Daniel Griffin to each person answering individually.

I as that individual would like to know so I can make the necessary choice as to remaining an unprotected person or receiving protection.

And, once again, many thanks to you all,

Stephen Ripple, D.O., M.D.

Evan writes:

Hi TWIV team,

Daniel Griffin talked today about the possibility that masks might be more effective than a minimally effective vaccine based on the estimated 50-75% effectiveness of masks vs. the nominal 50% threshold for vaccine approval.

I think Daniel may have underplayed this difference.  An important distinction is that masks, like physical distancing are effective at preventing infection, while the primary endpoint for vaccine approval has been repeatedly described as prevention of disease.  This means that masks could be significantly more effective at actually reducing the virus prevalence in the population. 


Anon writes:

With all this talk lately about how Churchill led, here is a quote that Dr. Griffin might like:

“Our peoples would rather know the truth, somber though it may be.”

Address to Congress, 12/26/1941

Liz writes:

Hey TWiV! 

Question for Dr. Griffin:

This may be kind of a stupid question, but should people with genetic thrombophilias consider their selves in a high risk group with respect to COVID19 complications? With all the talk of blood clots that seems like a given, but I haven’t found much discussion of this or any studies about it (and I’ve searched). Do you know of any?

I am heterozygous for the Factor V Leiden mutation (never had a clot myself, but my aunt did and thus I got tested). Otherwise I don’t have any other known risk factors (I’m in my early 30s, not overweight, female, no lung or immune problems, never smoker, etc), so have been thinking of myself as low-risk and offering to do things (like grocery shop, maybe be a poll worker) for people who are higher risk. But maybe I shouldn’t think this way? 

Ironically, my wife has no genetic risk factors for blood clots (she’s been tested for all the known ones TWICE), but had an asymptomatic DVT that resulted in multiple PEs about 7 years ago. She’s since fully recovered and been told to never take estrogen-containing drugs again but otherwise given no restrictions. Should she also be considering herself high risk for COVID19 complications because of this? 

Thanks for all the amazing work you do. Love the pod. 


Ben writes:

Dear TWIV,

A few episodes ago one of you gave a short riff on the concept of equilibrium between a virus and its host. The idea was that herd immunity was only one form an equilibrium might take, and there were other examples of how equilibria are achieved. I take it that not all these forms are benign, in fact far from it, though many are. I began to think about what an eventual SARS- COV-2 equilibrium would look like, compared to other viruses, like influenza. One hypothesis is that SARS-COV-2’s equilibrium results in it being another common cold coronavirus, dangerous to the frail, but otherwise largely benign. Compare that to influenza’s current equilibrium, killing 290,000+ worldwide, year after year after year after year. I don’t think this insight (such as it is) has any import for current policies – one of my comparands is, after all, still a hypothesis, and continued masking and distancing can save many lives on our way to any eventual equilibrium. Perhaps it serves more to remind us how bad influenza really is. But a balanced consideration of which is worse, Covid or influenza, may have more to it, in the fullness of time, than immediately meets the eye.


USAF Retired
Palmdale, CA

Greg writes:


I am writing outside of Austin, TX near Driftwood. Rich will surely know where I’m referencing. It is 76 F and it’s a beautiful day to be alive. I am (just) an ER doc that found you when EMRAP, an ER educational series, mentioned you in March. TWiV has become my favorite new entry on my busy podcast feed. 

I have become obsessed with this pandemic. It offers so much to learn and explore regarding a vast number of disciplines…virology, and more broadly, microbiology, epidemiology, medicine, economics, and sociology. It has cast light on our society’s structural racism igniting uncomfortable, yet necessary, conversations. It has revealed humanity’s potential for good in the face of global adversity. If the pandemic wouldn’t have so much suffering, death, and activity restriction, I would feel fortunate to be living through it.

But that is not why I write. It’s clear you know those things. Instead, I want to share an experience and a passion as they relate to the pandemic. 

The first is a weird phenomenon I experienced over the last months. I knew something was happening. I just didn’t consciously understand it until you pointed to this podcast by Thalia Gigerenzer. After listening, I realized I wasn’t alone. I had developed a friendship with people I’ve never met in person. You’ve mentioned this before, but your conversations really do make me feel like I’m sitting at the lunch table discussing virology and this pandemic with my friends. As a result, when I’m at that “lunch table”, I get an overwhelming sense that it’s going to be OK.  

Your conversations take me back to one of my happiest times…college at Washington University in St Louis. I almost went down the microbiology career track. I became enamored with molecular biology and spent a semester in Eric Richard’s lab back in 1995. Apropos to today’s conversations, I was playing around with PCR. Regarding TWiV, I love the thoughtful conversations, the banter, the reviews of the important papers, the interviews, really all of it. I even love the misspeaks and medical slip-ups which remind me that we are all human (and that you all are not physicians which I sometimes forget). Btw, Daniel Griffin is very good. His breadth of medical knowledge and ability to explain complex topics are excellent.

None of that compelled me to write, but without this context, the real reason would be out of context. What really compelled me was Vincent’s apology to Dickson. It really touched me. We’re all aware that we are often harshest to the people we are closest to. Regardless, the apology was heartfelt, needed, had no excuses, and was direct. Dickson’s acceptance was touching and on point as well. The apology was needed. It is what friends do, and it re-enforced why you all are important to me. 

The second reason I write is related to something that I think you and TWiV Nation might find valuable. I started writing about the pandemic to friends and family back in mid-March. I write as a scientifically minded ER doc attempting to explain all relevant pandemic and medical science to the non-medical and non-scientific crowd. It took the form of “Letters to Humans.” They were daily for about 1.5 months and now they are weekly. The recipient list grew to the point that Gmail would not let me send them from my personal email. Then recently I migrated them to a website – (here is the about page). The 70 plus letters are tagged and searchable. I reference TWiV a lot linking to short “highlights” – insightful summaries and important tidbits. Here are some of the letters I would point you to if you’re interested:

The letter, Postscripts Rock, is where I wrote what TWiV has become for me. It is about ½ way down. 

The now infamous 640 Episode was covered in Game Changer. 

A couple of other ones where TWiV is prominently mentioned:

To Test or Not to Test

Good Science Takes What?

Mutations Don’t Matter

If I were to direct you to every letter where TWiV is referenced, I would literally have to list over half of them. 

Please share While many won’t listen to a 2+ hr podcast, good scientifically minded and thoughtful information is important and unfortunately hard for many to find. Perhaps TWiV Nation can use the Letters to inform their friends and family. Importantly, these Letters are a way your impact is being amplified. 

Keep on TWiVing – what you are doing matters… thank you.  

And now to my standard salutation… 

Stay emotionally connected and physically distant,


PS: Regarding the glasses fogging in Episode 665. I’m glad Vincent mentioned the JAMA Ophtho article that he and Daniel discussed in the medical update portion. The article noted the observation that glasses-wearing folks have lower hospitalization rates than the glasses-less crowd. With all this focus on masks, we seem to be ignoring the eyeballs. As a person who wore a mask even pre-pandemic when at work during procedures, I’d like to point out two things. Glasses are fogging because there is not a good seal around the nose piece. Notably, I was able to essentially eliminate fogging when wearing a non-medical mask with a simple plastic nose clip I found on Etsy. Secondly, please read What the heck is Doffing where I discuss Advanced Maneuver #21. This entails placing a little paper tape on the nasal bridge to create a good seal (there is an accompanying picture). One piece of paper tape can last longer than you would guess. I guarantee both will eliminate or at least greatly reduce fogging. This should allow people to keep wearing their vision-enhancing eye protection! 

Lowell writes:

While I did notice you shushing Dickson a couple of times, I would have been shushing him as well.  You did well to apologize and he deserved it, but keep your chin up for you are a good guy.

LT Midla

(Practicing large animal veterinarian for 24 years – joined Merck 4 years ago)  

Lowell T. Midla VMD, MS
Merck Animal Health

David writes:

Dear TWIV — I’ve been listening fairly religiously since about April.  I now find myself very confused about some SARS-Cov-2 matters that I thought were settled a while ago.

When discussing vaccines, you all noted the difference between vaccines that prevent infection and those that prevent disease.  And you recently noted that most of the vaccines in trials are to prevent disease, not infection. You then voiced significant concern that vaccines that only prevent disease will still leave people at great risk because those who have the vaccine can still get infected with the virus and spread it to others.

But!  I thought it was fairly well-settled that infected people didn’t spread the virus until they had an elevated viral load — usually as a precursor to disease.  In other words, although there is “asymptomatic” transmission, this was almost always “presymptomatic.”  Just prior to the onset of signs/symptoms, a person’s viral load increased significantly and that person could start shedding the virus.  I assumed that the corollary (contrapositive? I don’t remember which) was that people who never progress to the point that they develop disease likely never have a viral load sufficient to be infectious.  In fact, I thought this was the basis for the Minna Testing Regime.

So, if people who never get a viral load high enough to get the disease don’t (or rarely?) shed the virus, isn’t a preventative vaccine sufficient to protect the spread of virus?  I understand that there may be a small percentage of people who never develop disease but also shed the virus, but is that enough to question whether the vaccine buys us a measure of security?  You all seemed to say that with a preventative vaccine, the populace is still at risk from asymptomatic spreading.  But if it’s truly asymptomatic and not presymptomatic, aren’t we fairly safe?

Similar question about the possibility of reinfection.  You discussed some evidence that at least two people have been reinfected with SARS-Cov-2.   I think Dr. Baric also said that this was to be expected — there are always some people who will get a virus after beating it once.  However, I think you also said that these two infected people didn’t get sick.  Well, if there is a risk of reinfection but it doesn’t carry risk of disease (or only a small risk), then can’t we assume that people who recovered from Covid-19 (or who have antibodies) are at very small risk of reinfection (2 proven cases out of millions of infected people) and even smaller risk of getting infected and having a viral load sufficient to infect others?

Maybe I’m looking at this all wrong. (And apologies if I’ve got some of my terminology wrong, my googling isn’t helping and I don’t have time to re-listen to the relevant podcasts).

Anyway, Thanks for all the great information.   Now if I can only explain to my friends on Facebook that just because they didn’t get very sick from Covid-19, it doesn’t mean that they have a “less dangerous strain” of the virus. 



David J. Stone | Attorney at Law | Bragar Eagel & Squire, P.C.

| New York, NY | 

Wayne writes:


Hope your well…just read this what’s up with the CDC?

Would you please bring this up on TWiV…we all need truthful, clear and scientific answers on this! Many feel the CDC is unreliable on issues concerning our virus issues!

BTW your apology to Dickson was very honorable and in the true Samurai fashion!

Stay strong and well…


Wayne G 

Wakayama JP