Highly mutated Omicron sub-lineages JN.1 and NB.1.8.1 harbor extensive spike changes, but their impact in preterm infants is poorly documented. We report a preterm male infant with three hospitalizations in seven weeks: severe SARS-CoV-2 ARDS at 40 days of life (DOL 40) requiring ventilation caused by JN.1.16, HCoV-OC43 infection at DOL 65, and a mild SARS-CoV-2 reinfection at DOL 87 due to NB.1.8.1, the first detection of this variant in Tunisia. Spike analysis showed a shared JN.1 backbone but distinct N-terminal and receptor-binding domain changes, supporting intra-Omicron reinfection driven by antigenic divergence and immature immunity and underscoring the value of pediatric genomic surveillance, including phylogenetic placement of case genomes within local Omicron diversity.
Hamzaoui et al. (Thu,) studied this question.