COVID-19を維持するためには、定期的なブースターが必要になりそうです。(Keeping COVID-19 in check likely to require periodic boosters)


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



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


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.