Abstract
<jats:p>Since late 2019, SARS-CoV-2 has diversified into numerous lineages, driving recurrent global waves of COVID-19. This narrative review synthesizes evidence on the evolutionary dynamics of SARS-CoV-2 with emphasis on Omicron subvariants, including JN.1 and its descendants, and emerging 2025 lineages (Nimbus and Stratus). We summarize major mechanisms shaping viral diversification – mutation/antigenic drift, recombination, and prolonged infection in immunocompromised hosts (including people living with HIV) – that can promote stepwise accumulation of immune-escape mutations. The review covers literature and genomic surveillance reports from 2019–2025 (WHO resources, GISAID, outbreak.info, PubMed/Scopus) and focuses on mutation profiles of key variants, global prevalence trends, and Ukraine-specific context. A dedicated section addresses why Ukraine – despite a relatively high HIV burden in Eastern Europe – has not been recognized as a major source of globally dominant variants of concern. Contributing factors discussed include limited sequencing coverage, reduced travel/export potential, expansion of ART, and stochastic and structural determinants required for widespread dissemination of newly arising lineages.We conclude that ongoing immune escape remains likely, underscoring the need for robust genomic surveillance, timely vaccine/therapeutic updates, and integration of COVID-19 monitoring with HIV services. </jats:p>