Wednesday, November 09, 2022

The Neurobiology of long COVID

A number of my friends have reported, having caught break thru Covid even after 3-5 vaccinations, and are having symptoms of long Covid such as brain fog, anosmia, and cognitive impairment. (I am extremely grateful, after five vaccinations, to still be Covid free.) For these friends as well as Mind Blog readers, I want to point to a special issue of Neuron and in particular one open source article "The neurobiology of long Covid," which describes the array of neurological symptoms and their possible causes.


  1. It's probably important to differentiate between breakthrough sars-cov-2 infection of the body serum proper and sars-cov-2 infection of the upper respiratory mucosa. The body serum and organs are protected by intramuscular vaccination via both antibody mechanism from memory B cells (igM and igG) and now tissue resident trained T cells.

    But the upper respiratory mucosa, where most sars-cov-2 infections start, is protected by igM and igA antibodies. And intramuscular vaccination does not lead to igG antibodies getting into the upper respiratory mucosa for longer than about a month. Additionally, there are no tissue resident T cells generated up there from intramuscular vaccination. There's nothing to quickly head off sars-cov-2 infections and spread even if COVID-19 pathology is prevented in the body.

    Intramuscular vaccination for sars-cov-2 does not seem to protect much, or long, against infection of the upper respiratory mucosa. And that sucks. Hopefully there will be a nebulized intranasal sars-cov-2 vaccine approved in the USA eventually to mitigate the continued infection and spread.

    Anyway, infection of the upper respiratory mucosa after intramuscular vaccination cannot really be considered a break through as those tissues are not protected. But plenty of igG antibodies do seep into the lower lungs from body serum and provide protection there and of the body organs. Breakthrough COVID-19 of the body serum and organs is the real breakthrough. We shouldn't conflate the two situations.

  2. The article is very well written and elucidates all the potential causes of long Covid. COVID-19 does seem to infect the brain cells (neurons) considering all these persistent and crippling cognitive deficit symptoms. Initially, they thought it was merely a respiratory infection, but loss of smell was a convincing indicator that it attacked the brain. There's actually a paper published in March 2020 explaining that loss of smell and taste gives hints that COVID-19 targets the nervous system.

    The medical community ignored those concerning neurological symptoms early on, which in result hindered research from taking a deeper look as to what precisely causes a wide array of cognitive issues. The research is moving relatively faster now, but they still don't seem to have zeroed in on as to what exactly drives these debilitating symptoms.
    Berlin cure is researching the drug "BC007" and many people are quite optimistic about that.

    It's very concerning given how many people have been affected globally and disabled some either temporarily or permanently.