Dr. Lepe writes:

Dear twivers:

 In episode 822, Rich Condit makes a very interesting recount on the origin of the variola virus that caused smallpox in humans stating, based on available evidence, a jump from rodents to humans around 2000 to 3000 years ago. 

In this regard, and given the general fact that around 7000 years ago humans domesticated cattle in Africa and The Middle East and the lucky immune cross reactivity of cowpox with smallpox, cattle was an intermediate host of smallpox between rodents and humans?

Also, in support of this general idea, it is generally assumed the success of Spaniards in conquering the new world was in great part due to the introduction of small pox and measles which were not present in the Americas nor was domesticated cattle in the continent.

Regarding variolation, Chinese were blowing crusts from lesions into the nose of uninfected people way before Jenner.

Thanks for your great contribution to viral knowledge.

Dr. Lepe.

Anonymous writes:

Thank-you for your wonderful podcasts. It is so heartwarming and reassuring to hear  discussion and debate as you decode and make sense of the scientific articles. In particular I very much appreciate listening to Vincent working through the publications. It is no easy feat to present the material in a way that deals with the findings, accounts for perspectives and scrutinizes the methodologies and makes them accessible to the audience. Bravo. 

I work for a health union as a researcher but my background is in sociology. And as part of my role I need help responding to a vaccine hesitant HCW. This individual contracted Covid-19 in early 2021. They recently had their antibody levels tested and according to their doctor the levels were very high or at the highest level the test registers. The HCW asks: If my antibodies are at the top of the range, why do I need a vaccine? 

I would like to provide a medically informed answer/ explanation that doesn’t simply refer to the policies in place (which, by the way,  I TOTALLY support) requiring the HCW to  be fully immunized.

I do know that antibodies are not the be all and end all, and that there is the adaptive arm of the immune system. I also know that we don’t know when and how quickly her antibody levels will drop. However I don’t know what or how to talk about other parts of the immune system and their role in protection. I have listened to TWIV 802 twice and will listen again.  And I am working my way through Lauren Sompayrac’ s How the Immune System Works (thanks for the recommendation.) Up to now I have had trouble reading immunology papers – it is so complex- but this text is helping. 

Can you please help? I am supposed to have a response by the end of October…. I doubt this query will make it onto one of the questions read on TWIV. And that’s fine by me as I would appreciate my name and role remaining entirely confidential…..

Any help appreciated, 


James writes:

An excellent question was asked in an email that Rich read on Molnupiravir and the effect of that mutation might have on creation of new variants. It apparently has only a 50% effectiveness against hospitalization, is this a factor? 

Enjoy the show, wish there was a transcript. 


Karin writes:

I’m just listening to your assurances that the virus will be destroyed but will not mutate.

Yes , if high concentrations are maintained , but low concentrations could lead to variants .

What  are the situations in which you could have low concentration exposure ? 

1) sharing of an expensive drug ( lower dose in fewer individuals) 

2) non compliance in drug taking 

3) will this drug survive in surface water subsequently used as drinking water ?