[conspire] COVID-19 "breakthrough" infections

[Deirdre Saoirse Moen]

One of the points I've made before (perhaps not here) is that immune systems are imperfect.

A common trigger of autoimmune diseases (e.g., MS) is viral or bacterial infections. The reason for this, basically, is immune system mis-guesses: each time a cell makes a new antibody, there's a chance it's making one to the wrong thing. If that gets amplified, it could be bad news for the rest of your life.

So one of the unstated advantages of vaccines is that you have an answer key for how to solve the test that a novel pathogen presents.

Specific example: ACE2 antibodies.

There was a study, and I can't refind it right now, analyzing the much-higher-than-expected deaths in certain groups of elderly men (70+). What they found was that many of them had ACE2 antibodies, which possibly (given that ACE2 regulates things like blood pressure) are associated with a bunch of other ailments, e.g., constrictive vasculopathies:

https://arthritis-research.biomedcentral.com/articles/10.1186/ar3012

There's been enough work done on anti-ACE2 that they now have treatments for it, but a lot of people died from COVID before they figured that out (and not every hospital will have the staff who think to test for it, or ready treatments for same).

I wish I could find that paper so I could see what work had been done that cites it. I'm fascinated that, given that SARS-CoV-2 uses ACE2 to enter cells, that ACE2 *antibodies* would make things worse. That seems counter-intuitive without further explanation.

There's a partial explanation in this paper, though:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7167588/

"We suggest that ACE2 down-regulation induced by the cell entry of SARS-CoV, NL63 and SARS-CoV-2 may be particularly detrimental in subjects with pre-existing ACE2 deficiency. Some degree of ACE2 deficiency has been associated with a variety of conditions including older age, hypertension, diabetes and cardiovascular disease, which also characterize people more likely to be infected and to present more severe complications."

Also interesting is the mention of heart failure and its correlation with ACE2 deficiency. (Of note to me, as my dad recently died, and one of the conditions that brought that on was congestive heart failure.)

-- 
  Deirdre Saoirse Moen
  deirdre at deirdre.net