Glenn writes:

TWIV Team:

I recently got my second booster-Pfizer-having had the original J&J and then a first Pfizer booster in November.

Got the shot Saturday afternoon and rested the rest of the day but felt OK and felt fine the next morning.

I am not a health nut but I do work out every morning and Sunday is my bike ride workout.  Feeling no ill effects from the vaccine I took off for an hour ride of about 12 miles. In the shower I am soaping up my left arm pit (shot in left arm) and it is like “Whoa-egg sized swelling!” After the shower I show my wife and assure her this is a good reaction. I am proud of my response!  By midday, the swelling goes down, then disappears, and I think “OK, the vaccine has done its job and now my germinal centers are resting”.

Next morning no swelling and I feel fine and go out for a 4 mile run.  Back in the shower, and repeat! Big swelling again! I say to my wife, “I think my workout is stimulating antibody response”.  She feigns interest and goes back to what she was doing.  Mid-day, swelling is gone.

Tuesday morning-body toning workout-shower-you guessed it! Swelling is back. So three consecutive morning workouts-three swelling events.

Wednesday I have my usual elliptical workout followed by a quick one mile run and no swelling this time.

So, I am curious as to if anyone has ever studied the effects of a good workout in conjunction with an effective vaccine to stimulate antibody production?  Sure seemed to be some connection there. Could be an emerging field of research!

PS-Love the show! I am same age as Vincent-born 1953. 

For Kathy-our daughter just graduated from MU with her Masters in Information Technology-Go Blue! We love Ann Arbor and going to be up there in July.

For Rich-my wife can trace her ancestry back to the Gotchers-supposedly Samuel sold his 4200 acres and now the town of Austin sits on most of it

Alan, Dickson, Breanne, Amy-I got nothing,.

Quick joke-which Paul McCartney song invites in a toxin:

Brother Michael, auntie Gin

Open the door and let ’em in, yeah


John writes:


My name is John Soro, I am a junior studying Biology at Caltech taking Bi 115: Viruses and Applications to Biological Systems. I was listening to TWiV 903 and had 2 questions:

1. Were there any hypotheses as to why total casualties from Omicron in just an 8-week period were so much worse than 23 weeks of Delta?

2. What are the possible mechanisms of Covid infection relapse? How is a virus able to reinfect a person shortly after it has just been cleared?



Rachel writes:

Hello and thank you for taking my question. The patience and endurance of the entire TWIV team is remarkable. We would be lost without you!

In 2020 I heard a lot about viral dose explaining how sick different people get from COVID. Is that still a thing, or is it a false hope that something explains illness severity not predicted by age, health, risk factors, etc.?


Reid writes:


Hope you are doing well! I am a student from Caltech in Bi 115, a course on viruses and their applications to biological systems. I had a quick question about the mice discussed in TWIV ep 900 (burning down the mouse). When you were discussing creating the immunodeficient mouse models for COVID-19 testing you mentioned that they were injected with human fetal liver stem cells to in theory create human hematopoiesis in mice. I am wondering, wouldn’t it be more valid to introduce stem cells from the adult bone marrow? Do you think this would affect the results considering most people who contract Covid have hematopoietic cell generation in the bone marrow? Since BM has a different microbiome and cells there have likely accumulated mutations.



Ben writes:

All –

I am a long-time supported/listener of TWIV and I can honestly say that your podcast kept me sane over the past two+ years with the deep fact-based approach to understanding the Sars COV-2 pandemic.  I am writing today to ask a question that has hit close to home for me.  Two weeks ago my wife experienced sudden hearing loss in her right ear.  Most of the loss is low frequency and her ENT has prescribed a course of oral corticosteroid (Prednisone) as well as a series of steroid injections into the ear.  She is right in the middle of the treatment and so far hasn’t seen any improvement.

What makes the story a bit more interesting/complicated is that she is double vaccinated (Pfizer) and has been boosted once.  While she has been careful to protect herself, she came down with COVID-19 in early April, and suffered a mild case (fever for a couple of days, sore throat, cough).  After making a full recovery in mid April she got what appeared to be pink eye, which self resolved in a few days.  In the middle of May (about a month after the COVID infection) she experienced the hearing loss issue.

From our investigation and speaking with the ENT doc, hearing loss is highly complex – and can be caused by a number of things.  One notable cause is viral – and related to inflammation.  It’s tempting to consider if her recent COVID-19 infection could be related to the hearing problem.  If it’s a potential cause, would it be at least worth trying an antiviral (since we’re throwing the kitchen sink at this problem) to see if it could help?

I’d deeply appreciate any insights from the TWIV team.

Kind regards,


Philip writes:

I find the weekly TWIV podcast to be informational for Covid-19.  I appreciate the Monkeypox updates as well.  

I’ve watched many of the older TWIV podcasts and find the episodes on polio, smallpox and rabies to be fascinating.  I only heard one reference to coronaviruses pre-Covid.

Rabies is an example of another disease that can be mitigated with vaccines.  It will always be in the wild but every case in domesticated animals is preventable as well as humans cases from those animals.

My insurance covers pre-exposure Rabies so I took advantage of that.  I do plan to spend a lot of time in Colombia in retirement.  The full post exposure treatment for those without pre-exposure vaccination is expensive and may be hard to find outside of the US.