Thread by @SystemsVirology

BREAKING🔔 The 19th paper from G2P-Japan🇯🇵 is out at Lancet Infectious Diseases @TheLancetInfDis . We elucidated the virological characteristics of new SARS-CoV-2 variant of interest, XBB.1.16 (aka #Arcturus) Please RT🔥 1/
thelancet.com/journals/lanin…

XBB.1.16 = XBB.1 + #F486P, #E180V, and #T478K in spike.
cf. XBB.1.5 = XBB.1 + #F486P in spike (i.e., XBB.1.16 = XBB.1.5 + #E180V and #T478K in spike). 2/

A phylogenetic tree shows that XBB.1.16 is a descendant of XBB.1, not of XBB.1.5. 3/

The relative basic reproduction number (Re) of XBB.1.16 is greater than that of XBB.1.5 in 🇮🇳🇺🇸🇸🇬🇦🇺, suggesting that XBB.1.16 will outcompete XBB.1.5 in the future. 4/

Pseudovirus experiments showed the increased infectivity by #T478K mutation. In contrast, #E180V decreased the infectivity. In total, the infectivity of XBB.1.16 was comparable to that of XBB.1.5. 5/

Neutralization assay showed that XBB.1.16 is robustly resistant to BA.2 breakthru infection sera (18-fold vs B.1.1) and BA.5 breakthru infection sera (37-fold vs B.1.1). 6/

Antigenic cartography shows that the antigenicity of XBB.1.16 is slightly different from that of XBB.1.5. 7/

Importantly, XBB.1.16 as well as the other XBB subvariants are sensitive to #sotrovimab, a therapeutic monoclonal antibody. 8/

In sum, our results suggest the increased fitness of XBB.1.16 may be due to (1) different antigenicity from XBB.1.5; and/or (2) the mutations in the non-S viral protein(s) that may contribute to increased viral growth efficiency. 9/9

PS - Yunlong @yunlong_cao explains more about XBB.1.16 and other new variants based on his data. This should add to and increase our knowledge🔥

https://twitter.com/yunlong_cao/status/1649523529422082048

Correction!
XBB.1.16 = XBB.1 + #F486P, #E180V, and #T478R in spike. cf. XBB.1.5 = XBB.1 + #F486P in spike (i.e., XBB.1.16 = XBB.1.5 + #E180V and #T478R in spike).

XBB.1 and XBB.1.5 harbor T478'K', while XBB.1.16 harbors T478'R'.

Correction (again)!

Pseudovirus experiments showed the increased infectivity by #T478R (not T478’K’!) mutation. In contrast, #E180V decreased the infectivity. In total, the infectivity of XBB.1.16 was comparable to that of XBB.1.5. 5/