COVID-19 enters cells by the Angiotensin-converting enzyme 2 (ACE2) receptor . This expressed in the lining cells of the lung called the bronchial epithelium The salmony orange (below). The light blue is skin cells. But this may be a reason why the lungs are targeted. Lack of early interferon response allows viral infection and then when you immune response kicks in, maybe you destroy the lining of the lungs. Likewise maybe the older and more infirm you you are, the less well you can deal with this and repair the damage. Therefore, as a Society it is important that the young whipper snappers (who are less at risk of fatalities) do not kill us old foggies off. I see in Russia it is suggested people get a 5 year prison sentence for not self-isolating.

The original SARS used this receptor

Cell entry of coronaviruses depends on binding of the viral spike (S) proteins to cellular receptors and on S protein priming by host cell proteases. SARS-CoV-2 uses the SARS-CoV receptor ACE2 for entry and the serine protease TMPRSS2 for S protein priming.


SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Hoffmann M, Kleine-Weber H, Schroeder S, Krüger N, Herrler T, Erichsen S, Schiergens TS, Herrler G, Wu NH, Nitsche A, Müller MA, Drosten C, Pöhlmann S. Cell. 2020 Mar 4. pii: S0092-8674(20)30229-4.

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  • I’m on an MS drug that specifically targets cd20, I am also significantly depleted on Cd4,6 and 8.
    I was on Tecfidera which resulted in repeated pneumonia (11 times ) over a 14 month period.
    My question is: I live in New Zealand, Covid19 is in Auckland but I live in another city- should I be proactive an self isolate, with my young family as well before it gets to our city?
    Thank you.

    • Is that CD6 or CD16 (monocyctes)/CD56 (natural killer cells). I would listen to NZ government advice

      and try to keep distance for people 1-2m if possible. If you start to self isolate now before its a problem you may never get out again.

      • Thank you.
        Sadly there is no specific advise being given by the government regarding immune compromised people and the actions they should be taking. 😔

          • Stay safe…Sorry I’m not more helpful. We had a co-worker arrive back from Northern Italy they volunteered to have two weeks holiday….only joking they were concerned about us and asked if they should self-isolate. It is all so hard to know what to do, The media is making us all go crazy. NHS 111 said work work work, but if this person doesn’t come back to work we cant provide some of our services

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