Thread by @ejustin46

𝗞𝗘𝗬 𝗦𝗧𝗨𝗗𝗬 :
"𝗔𝗻 𝗮𝗻𝗰𝗲𝘀𝘁𝗿𝗮𝗹 𝗦𝗔𝗥𝗦-𝗖𝗼𝗩-2 𝘃𝗮𝗰𝗰𝗶𝗻𝗲 𝗶𝗻𝗱𝘂𝗰𝗲𝘀 𝗮𝗻𝘁𝗶-𝗢𝗺𝗶𝗰𝗿𝗼𝗻 𝘃𝗮𝗿𝗶𝗮𝗻𝘁𝘀 𝗮𝗻𝘁𝗶𝗯𝗼𝗱𝗶𝗲𝘀 𝗯𝘆 𝗵𝘆𝗽𝗲𝗿𝗺𝘂𝘁𝗮𝘁𝗶𝗼𝗻"

nature.com/articles/s4146…

2) The study aimed to understand how repeated vaccination with the ancestral SARS-CoV-2 mRNA vaccine induces antibodies that can neutralize Omicron variants, which have mutations that allow immune escape.

3) They analyzed blood samples from 41 individuals who received three doses of the BNT162b2 mRNA vaccine. Samples were collected at various time points to track the immune response.

4) Analysis of B-cell receptor repertoires found that after the third dose, specific B-cell clones accumulated mutations (somatic hypermutation) that allowed them to bind both the ancestral spike protein and Omicron spike protein.

5) Certain B-cell receptor clones became prevalent after the third dose, particularly clones using the IGHV3-53/IGHV3-66 genes. Accumulation of mutations in these clones increased their affinity for both ancestral and Omicron spike proteins.

6) Functional testing confirmed that antibodies produced by these mutated B-cell clones could neutralize not just the original virus strain but also Alpha, Beta, Gamma, Delta and early Omicron variants in vitro.

7) The accumulation of mutations after the third dose seemed to expand the specificity of the B-cell receptor repertoire to recognize newer Omicron subvariants that emerged later, like BA.1, BQ.1.1, XBB.1.5, and XBB.1.16.

In summary, repeated vaccination induced ...

8) ... somatic hypermutation of antibody-producing B-cells, which helped generate antibodies that could neutralize diverse Omicron variants through cross-reactive binding to the spike protein. This may be a protective immune mechanism against viral variants.

Thanks for reading🙏