ブースターが効果を発揮するには、COVID-19ウイルスの原型とは大きく異なる亜種をターゲットにする必要がある To be effective, boosters should target variants widely different from COVID-19 virus’s original strain
2023-04-03 ワシントン大学セントルイス校
このブースターにより、新たに出現した変異体を含め、広範囲に中和化能力を持つ抗体反応を引き出すことができると研究者は指摘している。
しかしながら、最初に投与されたワクチンによって引き起こされた抗体が新たな変異体に対して効果を示さなくなることがあるため、これに対応するためには、新しいブースターショットを定期的に投与する必要があるとも述べている。
<関連情報>
- https://source.wustl.edu/2023/04/keeping-covid-19-in-check-likely-to-require-periodic-boosters/
- https://medicine.wustl.edu/news/updated-covid-19-boosters-can-generate-a-broad-antibody-response-against-new-variants/
- https://www.nature.com/articles/s41586-023-06025-4
SARS-CoV-2 オミクロンブースティングにより、ヒトでデノボB細胞応答が誘導される。 SARS-CoV-2 Omicron boosting induces de novo B cell response in humans
Wafaa B. Alsoussi,Sameer Kumar Malladi,Julian Q. Zhou,Zhuoming Liu,Baoling Ying,Wooseob Kim,Aaron J. Schmitz,Tingting Lei,Stephen C. Horvath,Alexandria J. Sturtz,Katherine M. McIntire,Birk Evavold,Fangjie Han,Suzanne M. Scheaffer,Isabella F. Fox,Senaa F. Mirza,Luis Parra-Rodriguez,Raffael Nachbagauer,Biliana Nestorova,Spyros Chalkias,Christopher W. Farnsworth,Michael K. Klebert,Iskra Pusic,Benjamin S. Strnad,William D. Middleton,Sharlene A. Teefey,Sean P. J. Whelan,Michael S. Diamond,Robert Paris,Jane A. O’Halloran,Rachel M. Presti,Jackson S. Turner & Ali H. Ellebedy
Nature Published:03 April 2023
DOI:https://doi.org/10.1038/s41586-023-06025-4
Abstract
The primary two-dose SARS-CoV-2 mRNA vaccine series are strongly immunogenic in humans, but the emergence of highly infectious variants necessitated additional doses and the development of new variant-derived vaccines1–4. SARS-CoV-2 booster immunizations in humans primarily recruit pre-existing memory B cells (MBCs)5–9. It remains unclear, however, whether the additional doses induce germinal centre (GC) reactions where reengaged B cells can further mature and whether variant-derived vaccines can elicit responses to variant-specific epitopes. Here, we show that boosting with either the original monovalent SARS-CoV-2 or bivalent B.1.351/B.1.617.2 (Beta/Delta) mRNA vaccines induces robust spike-specific GC B cell responses in humans. The GC response persisted for at least eight weeks, leading to significantly more mutated antigen-specific bone marrow plasma cell and MBC compartments. All MBC-derived spike-binding monoclonal antibodies (mAbs, n=766) isolated from individuals boosted with either the original SARS-CoV-2 spike, bivalent Beta/Delta, or a monovalent Omicron BA.1-based vaccine recognized the original SARS-CoV-2 spike protein. Nonetheless, by using a more targeted sorting approach we isolated mAbs that recognized the BA.1 spike protein but not the original SARS-CoV-2 spike from the mRNA-1273.529 boosted individuals. The latter mAbs were less mutated and recognized novel epitopes within the spike protein, suggesting a naïve B cell origin. Thus, SARS-CoV-2 booster immunizations in humans induce robust GC B cell responses and can generate de novo B cell responses targeting variant-specific epitopes.
