4. Resumo em inglês (abstract): The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), initially detected in December 2019 in Wuhan, China, is the causative agent of a pandemic responsible for over 6.5 million deaths worldwide as of March 2022. Brazil accounts for approximately 700,000 of these deaths, with its highest lethality rates recorded during the spread of the Zeta, Gamma, Delta, and Omicron variants, identified by the World Health Organization in January 2021. In the state of Rio Grande do Norte, the circulation of Gamma and Delta variants, for example, coincided with increases in the number of cases and deaths. To understand the spatial dynamics of concern variants in Rio Grande do Norte, phylogenetic techniques with a maximum-likelihood statistical framework were applied to a dataset consisting of sequences between November 2020 and March 2022, representing a significant fraction (>68%) of the total sequences from Rio Grande do Norte (nTOTAL=1702) during this period. The epidemiological profile of the epidemic in the state demonstrated that the Gamma period coincided with the peak in the number of cases, deaths, and lethality (~4%), decreasing only when Delta was introduced. Phylogenetic analysis revealed a large number of external introductions, with 100% from other Brazilian states during the Zeta and Delta periods, 98% from other Brazilian states and 2% from other countries during the Gamma period, while in Omicron, there were 36% from other countries and 64% from Brazil. Regarding internal introductions among immediate regions, Natal stood out as the main origin in all lineages. Therefore, with the resumption of urban mobility and incipient vaccination, the P.2, P.1, AY.99.2, BA.1, and BA.1.1 lineages in Rio Grande do Norte established multiple simultaneous transmission networks, reaching all regions of the state, overloading the local healthcare system, and increasing the infection's lethality. In the face of the continuous circulation of the SARS-CoV-2 virus in the country and the possibility of new viral emergencies, understanding the local dynamics of viral spread is an essential tool in the development of efficient and scientifically-based public policies.