BREAKING🔔 A new preprint from G2P-Japan🇯🇵 is out at bioRxiv @biorxivpreprint. We evaluated the antiviral humoral immunity induced by breakthrough infection (BTI) of XBB subvariants and its effect against a new one, EG.5. Please RT. 1/
biorxiv.org
biorxiv.org
Currently, a subvariant of XBB.1.9, EG.5 (aka XBB.1.9.2.5) is well documented in Twitter (maybe aka #X) and elsewhere.
EG.5.1 S = XBB.1.9.2 S + Q52H + F456L, and XBB.1.9.2 S = XBB.1.5 S. 2/
EG.5.1 S = XBB.1.9.2 S + Q52H + F456L, and XBB.1.9.2 S = XBB.1.5 S. 2/
On July 19, #WHO has classified EG.5 as a ‘variant under monitoring’. 3/
First, Jumpei @jampei2 showed that the relative reproduction number (Re) of EG.5.1 is ~1.2-fold greater than that of XBB.1.5, suggesting that EG.5.1 can be potentially a new predominant variant in the near future. 4/
Pseudovirus assay showed that the infectivity of EG.1.5 is lower than that of XBB.1.5/1.9.2, suggesting that the greater Re of EG.1.5 is NOT due to its increased infectivity. 5/
Neutralization assay using the BTI sera of XBB subvariants (XBB.1.5, XBB.1.9 & XBB.1.16) showed that EG.5.1 is NOT resistant to these sera, suggesting that the emergence and spread of EG.5.1 is NOT due to the evasion from the XBB-induced humoral immunity. 6/
However, strikingly, we found that the antiviral activity of XBB BTI against XBB subvariants infected is ~8-fold lower than that against ancestral B.1.1❗️ 7/
Previous studies (including ours) have shown that the antiviral activity of Omicron BTI (BA.1, BA.2 & BA.5) against the Omicron subvariants infected is lower than that against ancestral B.1.1, but the difference is only 2-3 fold. 8/
These results suggest that the extent of antiviral humoral immunity induced by the BTI with XBB subvariants is lower than that of the previous Omicron subvariants. BTI with XBB subvariants, including XBB.1.5, may not be able to induce a significant level of humoral immunity. 9/
Finally, “How is EG.5.1 spreading efficiently?” - Regarding this, “the COVID predictor”, Dr. Yunlong Cao @yunlong_cao has shown that EG.5 is resistant to “BA.5 BTI + XBB BTI” sera. 10/
Due to the complex history of vaccines & infections, the immune background against SARS-CoV-2 is now diverse. This complex immune status may be a factor in the simultaneous emergence of multiple variants and convergent evolution. Frankly, there are still so many unknowns... 11/11
Loading suggestions...