Literature update ViVa week 27-2026

1. JN.1 booster shows surprising reach: cross-hits BA.3.2.2 and keeps a monoclonal option alive In this short immunogenicity study, 25 adults receiving a monovalent JN.1 mRNA vaccine provided serum before and about 12 days after vaccination; participants were stratified by anti-nucleocapsid status to distinguish infection naïve (n=13) from previously infected (n=12) individuals. Neutralizing titers rose significantly against eight SARS-CoV-2 variants in both groups, with the largest fold rise against JN.1 in N-negative vaccinees (GMT 21 to 227; 10.8 fold). Cross-neutralization of the antigenically distant BA.3.2.2 lineage was observed but at lower titers (N-negative GMT 23 to 76; N-positive 69 to 447). Antigenic cartography showed BA.3.2.2 as isolated from JN.1 descendants, while monoclonal antibody testing revealed that AZD3152/sipavibart retained potent activity against BA.3.2.2 but lost activity against F456L harboring JN.1 descendants; VYD222/pemivibart and SA55 maintained broader neutralization. The authors attribute BA.3.2.2 cross-neutralization to its retention of wild-type F456, preserving class 1/2 antibody...