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SARS-CoV-2 mRNA vaccines induce persistent human germinal centre responses

Shiloh

Editor, Senior Moderator
Source: https://www.nature.com/articles/s41586-021-03738-2



Published: 28 June 2021
This is an unedited manuscript that has been accepted for publication. Nature Research are providing this early version of the manuscript as a service to our authors and readers. The manuscript will undergo copyediting, typesetting and a proof review before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers apply.

SARS-CoV-2 mRNA vaccines induce persistent human germinal centre responses

Jackson S. Turner, Jane A. O’Halloran, Elizaveta Kalaidina, Wooseob Kim, Aaron J. Schmitz, Julian Q. Zhou, Tingting Lei, Mahima Thapa, Rita E. Chen, James Brett Case, Fatima Amanat, Adriana M. Rauseo, Alem Haile, Xuping Xie, Michael K. Klebert, Teresa Suessen, William D. Middleton, Pei-Yong Shi, Florian Krammer, Sharlene A. Teefey, Michael S. Diamond, Rachel M. Presti & Ali H. Ellebedy


Abstract

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA)-based vaccines are ~95% effective in preventing coronavirus disease 20191–5. The dynamics of antibody secreting plasmablasts (PBs) and germinal centre (GC) B cells induced by these vaccines in humans remain unclear. We examined antigen-specific B cell responses in peripheral blood (n=41) and draining lymph nodes (LNs) in 14 individuals who received two doses of BNT162b2, an mRNA-based vaccine encoding full-length SARS-CoV-2 spike (S) gene1. Circulating IgG- and IgA-secreting PBs targeting the S protein peaked one week after the second immunization then declined, becoming undetectable three weeks later. These PB responses preceded maximal levels of serum anti-S binding and neutralizing antibodies to an early circulating SARS-CoV-2 strain as well as emerging variants, especially in individuals previously infected with SARS-CoV-2, who produced the most robust serologic responses. By examining fine needle aspirates (FNAs) of draining axillary LNs, we identified GC B cells that bound S protein in all participants sampled after primary immunization. Remarkably, high frequencies of S-binding GC B cells and PBs were sustained in these draining LNs for at least twelve weeks after the booster immunization. S-binding GC B cell-derived monoclonal antibodies predominantly targeted the receptor binding domain of the S protein, with fewer clones binding to the N-terminal domain or to epitopes shared with the S proteins of the human betacoronaviruses OC43 and HKU1. The latter cross-reactive B cell clones had higher levels of somatic hypermutation compared to those that only recognized SARS-CoV-2 S protein, suggesting a memory B cell origin. Our studies demonstrate that SARS-CoV-2 mRNA-based vaccination of humans induces a persistent GC B cell response, enabling the generation of robust humoral immunity.
 
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Three weeks after the first dose, all 14 participants had formed germinal centers with B cells producing antibodies that target a key SARS-CoV-2 protein. The response expanded greatly after the booster shot and then stayed high. Even 15 weeks after the first dose, eight of 10 people still had detectable germinal centers containing B cells targeting the virus.

“This is evidence of a really robust immune response,” Presti said. “Your immune system uses germinal centers to perfect the antibodies so they can bind well and last as long as possible. The antibodies in the blood are the end result of the process, but the germinal center is where it is happening.”

The researchers also obtained blood samples from 41 people who received the Pfizer vaccine, including eight who previously had been infected with the virus that causes COVID-19. Samples were obtained prior to the administration of each dose of the vaccine, as well as at weeks four, five, seven and 15 after the first dose. In people without prior exposure to the virus, antibody levels rose slowly after the first dose and peaked one week after the second. People who previously had been infected already had antibodies in their blood before the first dose. Their levels shot up quickly after the first dose and peaked higher than the uninfected participants’ levels.

more..

https://medicine.wustl.edu/news/covi...ting-immunity/

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Disclosure: I am fully vaccinated with Moderna.


I really hope this is true in the mass population, in real life settings, when exposed to virus shedding people. Everyone should still be cautious. Vaccines are not perfect. They will not protect everyone all the time. We are early in this disease. One year is nothing. We don't know what we don't know.

Only you can take care of you.
 
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