BREAKING🔔 The 14th preprint from G2P-Japan🇯🇵 is out @biorxivpreprint. We illuminated the evolutionary rule underlying the convergent evolution of #Omicron and the virological characteristics of one of the latest lineages of concern, BQ.1.1. Please RT. 1/ biorxiv.org/content/10.110…
In late 2022, the Omicron subvariants have highly diversified. However, some lineages have convergently acquired amino acid substitutions at five critical residues in the spike protein: R346, K444, L452, N460 and F486. 2/
Here, we, particularly two shining young talents, @jampei2 & @SpyrosLytras, performed phylogenetic and epidemic dynamics analyses and showed that Omicron subvariants independently increased their viral fitness by acquiring the convergent substitutions. 4/
All five convergent substitutions (R346T, K444T, L452R, N460K & F486V) contributed to increasing relative basic reproduction number (Re) (left), and BQ.1.1, which harbors all five convergent substitutions, showed the highest fitness among the viruses investigated (right). 5/
Neutralization assay showed that BQ.1.1 is more resistant to breakthrough BA.2/5 infection sera than BA.5. 6/
We have shown lines of data suggesting the close association of viral fusogenicity and intrinsic pathogenicity. For instance, both BA.5 (the link is shown below⬇️) and BA.2.75, descendants of BA.2, are more fusogenic and pathogenic than parental BA.2. 7/
Notably, the BQ.1.1 spike exhibited greater fusogenicity than the BA.5 spike, suggesting that BQ.1.1 is more pathogenic than BA.5. 8/
However, unexpectedly, experiments using hamsters showed that the pathogenicity of BQ.1.1 in hamsters is comparable to or even lower than that of BA.5.
Our multiscale investigations provide insights into the evolutionary trajectory of Omicron subvariants. 9/9
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BREAKING🔔 A new study from G2P-Japan🇯🇵, led by Keiya @Keiya717, is out at @biorxivpreprint. We assessed the humoral immunity induced by JN.1 mRNA vaccines against a broad range of SARS-CoV-2 variants including JN.1, KP.3.1.1 & XEC. Please repost🔥 1/ biorxiv.org/content/10.110…
In this study, we used 2 mRNA vaccines, one is from Pfizer/BioNTech🇺🇸🇩🇪, while another is from Daiichi-Sankyo🇯🇵. The good news is that there are no significant differences between them and both broadly neutralized a variety of SARS-CoV-2 including JN.1, KP.3.1.1 and XEC. 2/
But there are two scientific interests.
First, compared to our recent study using JN.1 and KP.3.3 breakthrough (i.e. natural) infection sera, antiviral humoral immunity against KP.3 and XEC was weakly induced. However, JN.1 mNRA vaccine can. Why🤔?? 3/
BREAKING🔔 A new study from G2P-Japan🇯🇵, led by Yu in my lab, is out at bioRxiv @biorxivpreprint. We elucidated the virological characteristics of SARS-CoV-2 #XEC. Please repost🔥 1/ biorxiv.org/content/10.110…
Compared with KP.3, #XEC harbors two spike substitutions, S:T22N and S:F59S. Recombination analysis by Shusuke @KawakuboShusuke showed that XEC is a recombinant lineage of KS.1.1 (JN.13.1.1.1) and KP.3.3 (JN.1.11.1.3.3) with a breakpoint at genomic position 21,738–22,599. 2/
Transmissibility/fitness (Re):
Molecular phylogenetic-epidemic dynamics modeling led by Jumpei @jampei2 and Kaho showed that the Re of #XEC is greater than that of KP.3.1.1, the most predominant variant in the world. 3/
BREAKING🔔 Here I want to quickly report our new results from G2P-Japan🇯🇵 before the preprint publication. We have elucidated the virological characteristics of SARS-CoV-2 KP.3.1.1 - a progeny of JN.1. Please RT🔥 1/
Cf.1 A new one, KP.2 (JN.1.11.1.2), has been already elucidated. 2/