Charles writes:

Hello TWiVers;

64F, and waiting for rain in Chapel Hill, NC.  It is nice at the moment.

I have a question about vaccines and sterilizing immunity.  I have no problem with the concept that vaccines do not provide sterilizing immunity for the long term.  My question is do the mRNA COVID-19 vaccines provide short term, say 60-90 day, sterilizing immunity?

If the answer is yes, or maybe, would that sterilizing immunity prevent people from becoming seropositive to the SARS-CoV-2 N protein during the 60-90 days?

If that is also yes or maybe, I have a suggestion for why the CDC’s MMWR that was discussed on TWiV 895 showed that younger people had a higher seroprevalence than older people.  Older people have a higher rate of vaccination.  If vaccination prevents N protein seroconversion for 60-90 days, that could be the reason for the lower seroprevalence.  Just fewer days when an infection would produce seroconversion in a vaccinated person.



Zokky writes:

The road to hell Is paved with good intentions

Thanks for all that you do

Its made the lockdowns bearable and kept my mind expanding in ways I didn’t feel qualified as a lay person.

Also took my mind off the sad events around the world where those less fortunate than us suffered difficulties beyond our understanding



Deborah writes:


I am a fan of TWIV and regularly listen to the podcasts on my long dog walks, occasionally needing to stop, rewind to hear something again. I am a clinician (Pediatric Infectious Diseases) and enjoy the clinical updates, but also the virology and immunology deep dives.

I was listening last week to the April 28th episode (TWiV #894-Dinner with the TMPRSS family) when, at the end, I heard you mention the book For the Love of Enzymes by Arthur Kornberg.

My dad, Bob Lehman, was Arthur’s post doc in St. Louis at Washington University when his Nobel prize winning work was done. They then both moved (with the rest of the department) from St. Louis to Stanford University, where they remained for many decades. My dad is also a lover of enzymes, and a few years later discovered the mechanism of DNA Ligase. 

My dad is still a member of Stanford’s biochemistry department, and at age 97 still participates actively in departmental activities,  even after giving up his lab many years ago.

I have attached a photo of them taken in their later years at Stanford. My dad is on the left and I have no idea the story behind the matching blue shirts!  When Arthur died, my dad lost a dear friend.

Arthur, who was an MD  (not a PhD, interestingly) was also a good family friend and actively supported my journey to medical school, and I will always treasure that.

You mentioned that he was married three times, and that is true. His first two wives predeceased him, which was quite sad, but we were always so happy that he found love and companionship throughout his life.

His legacy continues, as you know two of his sons are accomplished scientists, and one of them (Roger) is also a Nobel prize recipient (father son Nobel Laureates! indeed!).

All the best. Looking forward to the next TWIV podcast!



Deborah Lehman, MD
Professor of Clinical Pediatrics
Assistant Dean for Student Affairs

Bill writes:

Ellen writes:


I’m in Minnesota (where it’s cold), and so occasionally hear Dr. Osterholm on local news talking about the pandemic. Today (May 2) I heard him on this segment ( ) of a local show talking about problems COVID-19 could pose in the future. One he raised at about 7 minutes 30 seconds was 

“We know that with coronaviruses, [if] you have a little bit of antibody, not a lot, or none at all, you’re in trouble. If you have none at all, you’ll get the disease, hopefully not be too serious. If you have a lot of antibody you may get the disease, hopefully it’ll be mild. But if you get that middle group, where it’s just a little bit of antibody, that sets off an immune response. This is just like dengue and hemorrhagic fever viruses, which are 30-40% of the time fatal.”

I have a couple questions. First, I was under the impression that the fatality rate of dengue after prior infection was due to having been previously infected with a different type of dengue, not the quantity of antibody. Is this accurate? 

Second, does this seem at all likely to happen with SARS-CoV-2?

Last, I’m not a science communicator or scientist, so I’m wondering what your thoughts are on saying this to the general public. It seems like it could make people very fearful about naturally declining antibody levels. 

Thank you,


Aidan writes:

Hi, The problem of the plurality of a “data point” is solved. Wittgensteins Tractatus logico-philosophicus 4.128

Logical forms are without number.

Hence there are no pre-eminent numbers

in logic, and hence there is no possibility of

philosophical monism or dualism, etc.

Since a point is an infinitesimal, it is an abstraction and therefore without number. Data can still be plural and involved with it.

Suellen writes:

Hey Vincent and all the TWIV team, including Dr. Daniel!

Wanted to pass along this epitope (haha) of a great show we get on PBS down here in the ATL. The show is “Your Fantastic Mind” and it’s produced by the Emory Brain Health Center. This particular epitope aired last season, but it is probably still relevant and contains a lot of great info on long COVID and what some doctors and researchers at Emory are doing to help patients. One patient is even a doctor himself! The segment is only about 15 minutes long, so it fits into even the busiest of days. The other half of the epitope is about  a new class of budding neurosurgeons, and that’s pretty interesting, too, although not COVID-related.

So enjoy, and if you want to watch more episodes they are all out there on the web.

Here is a link: 

Your Fantastic Mind Season 3 Ep 2: Long COVID and Making of a Brain Surgeon (Full Episode)

\While I love the weather down here, I hate the politics. But it’s really nice to live near Emory, GA State, GA Southern, GA Tech, and the CDC!

Your correspondent in Roswell —