Thread by @SystemsVirology

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/

https://x.com/G2PJapan/status/1793071073006866929

Cf.2 Another new ones, KP.3 (JN.1.11.1.3), LB.1 (JN.1.9.2.1) and KP.2.3 (JN.1.11.1.2.3), have also been already elucidated. 3/

https://x.com/G2PJapan/status/1806464135988924679

Here we focused on a new one, KP.3.1.1 (JN.1.11.1.3.1.1). This variant harbors these mutations.
KP.3.1.1 spike = KP.3 spike + S31del. 4/

Transmissibility/fitness (Re): molecular phylogenetic-epidemic dynamics modeling led by Jumpei @jampei2 and Kaho showed that the Re of KP.3.1.1 is greater than those of the other JN.1 subvariants. 5/

Pseudovirus infectivity: KP.3.1.1 is more infectious than KP.3. 6/

Immune resistance: the 50% neutralization values of breakthrough infection (BTI) sera with XBB.1.5, EG.5.1, HK.3 and JN.1 as well as XBB.1.5 vaccine sera against KP.3.1.1 were significantly lower than those against KP.3 and even KP.2.3 in some cases🔥 7/

These results suggest that KP.3.1.1 has the potential to be predominant, due to its higher infectivity and increased immune evasion. In particular, #S31del in spike, the common mutation in KP.3.1.1, LB.1 and KP.2.3, is likely to be a key mutation. 8/8