Thread by @abledoc

Germinal Centre defects in severe COVID19 patients who died cripples effective antibody response. It probably explains why it takes upto 4-5 weeks (incubation upto 2, then 2-3) for antibodies to form. 10% produce no antibodies at all. #CovidImmunity
sciencemag.org/news/2020/08/c…

Short lived nature of the antibody response after COVID19 infection makes dreams of Herd immunity from natural infections a mirage if ever it was even a thing. OTOH, vaccines "may" produce long lived antibodies, particularly with the RNA vaccines.
sciencemag.org/news/2020/08/s…

Defects in Germinal center formation explains the short duration and/or lack of effective antibody response in COVID19. Most antibodies are derived from non-GC Bcells. TFh differentiation defects underlie the lack of Bcl6+ TFh & Follicular Bcells. Bodes poorly for Herd immunity.

However effective vaccines can overcome the GC formation defect and potentially induce long lived antibodies after vaccination.
Poor antibody response is a feature of other "human" coronaviruses & we should be working on their vaccines too.

How TNFa disrupts Germinal Centre formation and prevents production of efficient antibodies during infections including viruses.
jimmunol.org/content/203/9/…

Administration of anti-TNFa antibiotics may be worth trying.
So far retrospective studies in Rheumatology patients have shown antiTNF therapies to be safe in COVID19.

Here is a review on Germinal Center Response and its role in high affiity, long-lived antibodiy response.
frontiersin.org/articles/10.33…