Comparative spatial–temporal analysis of SARS-CoV-2 lineages B.1.1.33 and BQ.1.1 Omicron variant across pandemic phases

The evolution of COVID-19 pandemic has been characterized by the rapid emergence of new SARS-CoV-2 variants, each of which poses unique challenges to public health. This study analyzes the dispersion profiles during the Pre-Omicron and Post-Omicron phases in different epidemiological contexts. The Brazilian state of Espirito Santo, despite its low population density, plays a critical role as a commercial hub due to its intense port activity, which may have contributed to COVID-19 cases and mortality rates being higher than the national average. The state recorded 34,000 confirmed cases and 377 deaths per 100,000 inhabitants. Genomic surveillance revealed that the Pre-Omicron phase was dominated by the B.1.1.33 lineage, characterized by localized intraregional circulation. In contrast, the Post-Omicron phase, dominated by the BQ.1.1 lineage, exhibited greater diversity in circulating lineages, increased international interactions, and rapid viral dissemination, highlighting distinct transmission dynamics between such periods. This study highlights the need for adaptive public health strategies that account for both viral behavior and regional socioeconomic factors, while highlighting the strategic importance of Espirito Santo in monitoring SARS-CoV-2 evolution.