#Neutralization and #Stability of #JN1-derived #LB1, #KP23, #KP3 and #KP311 #Subvariants http://biorxiv.org/cgi/content/short/2024.09.04.611219v1?rss=1

We report on the neutralizing #antibody (nAb) #escape, infectivity, #fusion, and stability of these subvariants-LB.1, KP.2.3, KP.3, and KP.3.1.1. Our findings demonstrate that all of these subvariants are highly evasive of nAbs elicited by bivalent #mRNA #vaccine, the #XBB15 monovalent mumps virus-based vaccine, or from infections during the BA.2.86/JN.1 wave.

Immunogenicity and #efficacy of #XBB15 rS #vaccine against the #EG51 #variant of #SARS-CoV-2 in Syrian #hamsters, J Virol.: https://journals.asm.org/doi/full/10.1128/jvi.00528-24?af=R

Thus, based on these study results, the protein-based XBB.1.5 vaccine is immunogenic and increased the breadth of protection against the Omicron EG.5.1 variant in the Syrian hamster model.

#SARS-CoV-2 #BA4/5 #infection triggers more cross-reactive FcγRIIIa signaling and #neutralization than #BA1, in the context of #hybrid #immunity, J Virol.: https://journals.asm.org/doi/full/10.1128/jvi.00678-24?af=R

Although this is consistent with enhanced neutralization and FcγRIIIa signaling breadth of BA.4/5 vaccine boosters, the reduced activity against #XBB15 supports the need to update vaccines with XBB sublineage immunogens to provide adequate coverage of these highly antibody evasive variants.

#Durability of #XBB15 #Vaccines against #Omicron #Subvariants, N Engl J Med.: https://www.nejm.org/doi/full/10.1056/NEJMc2402779?query=TOC&cid=DM2342986_Non_Subscriber&bid=-1971795569

Overall, the XBB.1.5 vaccines were effective against omicron subvariants, although less so against #JN1. Effectiveness was greater against #hospitalization and #death than against infection, and it waned moderately from its peak over time. The ramping and waning patterns were broadly similar to those of the bivalent boosters against BQ.1–BQ.1.1 and XBB–XBB.1.5.3

Characteristics of #JN1-derived #SarsCoV2 #subvariants #SLip, #FLiRT, and #KP2 in neutralization #escape, #infectivity and membrane #fusion http://biorxiv.org/cgi/content/short/2024.05.20.595020v1?rss=1

Interestingly, #antibodies in #XBB15 monovalent vaccinated hamster sera robustly neutralized FLiRT and KP.2 but had reduced efficiency for SLip.

#Virological characteristics of the #SarsCoV2 #KP2 #variant http://biorxiv.org/cgi/content/short/2024.04.24.590786v1?rss=1

Particularly, KP.2 shows the most significant #resistance to the #sera of monovalent #XBB15 #vaccinee without #infection (3.1-fold) as well as those who with infection (1.8-fold). Altogether, these results suggest that the increased immune resistance ability of KP.2 partially contributes to the higher Re more than previous variants including JN.1.

Evaluating #Humoral #Immunity Elicited by #XBB15 Monovalent #COVID19 #Vaccine, Emerg Infect Dis.: https://wwwnc.cdc.gov/eid/article/30/6/24-0051_article

We report boosting of #IgG (2.1×), #IgA (1.5×), and total IgG/A/M (1.7×) targeting the #spike receptor-binding domain and neutralizing titers against WA1 (2.2×), XBB.1.5 (7.4×), #EG51 (10.5×), and #JN1 (4.7×) variants.

#XBB15 monovalent #mRNA #vaccine #booster elicits robust neutralizing #antibodies against #XBB subvariants and #JN1, Cell Host Microbe: https://doi.org/10.1016/j.chom.2024.01.014

• An XBB.1.5 booster markedly enhanced neutralization of SARS-CoV-2, including JN.1
• An XBB.1.5 booster induced similar antibody titers to XBB infection
• Omicron infection followed by XBB.1.5 booster yielded the highest antibody titers
• Our findings supported recommendations for broad use of the updated XBB.1.5 booster