Phylogenetic analysis of hCoV-19 (SARS-CoV-2) genomes provides a detailed view of how viral lineages have been introduced, established, and evolved across Oceania. An Oceania-focused phylogenetic tree emphasizes regional transmission patterns shaped by geographic isolation and population movement, while still incorporating a limited number of genomes from other regions to retain global evolutionary context.
This time-resolved reconstruction spans the full course of the pandemic, from the earliest available sequences in 2020 through to the most recent genomic submissions. By integrating sampling dates into the analysis, the tree captures both early introduction events and later periods of lineage diversification, illustrating how hCoV-19 (SARS-CoV-2) diversity has changed across distinct epidemic phases.
The most recent branches of the phylogenetic tree are dominated by genomes assigned to NB.1.8.1, which currently represent the predominant lineages among newly deposited sequences from Oceania. These viruses cluster near the tips of the tree, consistent with their recent emergence and ongoing circulation. In addition, PE.1.4 and PQ.2 continue to be observed, reflecting sustained diversification within Omicron-derived genetic backgrounds.
The branching patterns reveal how contemporary lineages descend from earlier variants, with mutation accumulation over time supporting molecular clock-based inference of divergence events.
Recent GISAID data indicate that Australia, New Zealand, and others are the principal contributors of hCoV-19 (SARS-CoV-2) genome sequences from Oceania in the current period. Concentrated sequencing efforts from these locations improve phylogenetic resolution and enable clearer identification of transmission clusters, while still allowing comparison with genomes sampled outside the region.
Although centered on Oceania, the inclusion of selected non-regional genomes provides reference points for assessing introductions and shared ancestry without detracting from the regional focus of the analysis.
An Oceania-focused hCoV-19 (SARS-CoV-2) phylogenetic tree offers important insight into how viral evolution unfolds in a geographically constrained setting. It supports genomic surveillance, clarifies lineage turnover following introduction events, and contributes to a broader understanding of hCoV-19 (SARS-CoV-2) evolution at both regional and global scales.
