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1.
Preprint in English | medRxiv | ID: ppmedrxiv-21266251

ABSTRACT

The SARS-CoV-2 Variant of Concern (VOC) Delta was first detected in India in October 2020. The first imported cases of the Delta variant in Brazil were identified in April 2021 in the Southern region, followed by more cases in different country regions during the following months. By early September 2021, Delta was already the dominant variant in the Southeastern (87%), Southern (73%), and Northeastern (52%) Brazilian regions. This work aimed to understand the spatiotemporal dissemination dynamics of Delta in Brazil. To this end, we employed a combination of Maximum Likelihood (ML) and Bayesian methods to reconstruct the evolutionary relationship of 2,264 of VOC Delta complete genomes (482 from this study) recovered across 21 out of 27 Brazilian federal units. Our phylogeographic analyses identified three major transmission clusters of Delta in Brazil. The clade BR-I (n = 1,560) arose in Rio de Janeiro in late April 2021 and was the major cluster behind the dissemination of the VOC Delta in the Southeastern, Northeastern, Northern, and Central-Western regions. The clade BR-II (n = 207) arose in the Parana state in late April 2021 and aggregated the largest fraction of sampled genomes from the Southern region. Lastly, the clade BR-III emerged in the Sao Paulo state in early June 2021 and remained mostly restricted to this state. In the rapid turnover of viral variants characteristic of the SARS-CoV-2 pandemic, Brazilian regions seem to occupy different stages of an increasing prevalence of the VOC Delta in their epidemic profiles. This process demands continuous genomic and epidemiological surveillance toward identifying and mitigating new introductions, limiting their dissemination, and preventing the establishment of more significant outbreaks in a population already heavily affected by the COVID-19 pandemic.

2.
Preprint in English | medRxiv | ID: ppmedrxiv-21265116

ABSTRACT

The COVID-19 epidemic in Brazil experienced two major country-wide lineage replacements, the first driven by the lineage P.2, formerly classified as variant of interest (VOI) Zeta in late 2020 and the second by the variant of concern (VOC) Gamma in early 2021. To better understand how these SARS-CoV-2 lineage turnovers occurred in Brazil, we analyzed 11,724 high-quality SARS-CoV-2 whole genomes of samples collected in different country regions between September 2020 and April 2021. Our findings indicate that the spatial dispersion of both variants in Brazil was driven by short and long-distance viral transmission. The lineage P.2 harboring Spike mutation E484K probably emerged around late July 2020 in the Rio de Janeiro (RJ) state, which contributed with most ([~]50%) inter-state viral disseminations, and only became locally established in most Brazilian states by October 2020. The VOC Gamma probably arose in November 2020 in the Amazonas (AM) state, which was responsible for 60-70% of the inter-state viral dissemination, and the earliest timing of community transmission of this VOC in many Brazilian states was already traced to December 2020. We estimate that variant Gamma was 1.56-3.06 more transmissible than variant P.2 co-circulating in RJ and that the median effective reproductive number (Re) of Gamma in RJ and SP states (Re = 1.59-1.91) was lower than in AM (Re = 3.55). In summary, although the epicenter of the lineage P.2 dissemination in Brazil was the heavily interconnected Southeastern region, it displayed a slower rate of spatial spread than the VOC Gamma originated in the more isolated Northern Brazilian region. Our findings also support that the VOC Gamma was more transmissible than lineage P.2, although the viral Re of the VOC varied according to the geographic context.

3.
Preprint in English | medRxiv | ID: ppmedrxiv-21260508

ABSTRACT

We report a genomic surveillance of SARS-CoV-2 lineages circulating in Parana, Southern Brazil, from March 2020 to April 2021. Our analysis, based on 333 genomes, revealed that the first variants detected in the state of Parana in March 2020 were the B.1.1.33 and B.1.1.28 variants. The variants B.1.1.28 and B.1.1.33 were predominant throughout 2020 until the introduction of the variant P.2 in August 2020 and a variant of concern (VOC), P.1, in January 2021. Phylogenetic analyses of the SARS-CoV-2 genomes that were previously classified as the VOC P.1 lineage by PANGO showed that some genomes from February to April 2021 branched in a monophyletic clade and that these samples grouped together with genomes recently described with the lineage P.1-like-II. An extended phylogenetic analysis, including SARS-CoV-2 genomes from all over Brazil, showed that the P.1-like-II lineage appears at a high frequency in the southern region of the country. The P.1-like-II lineage genomes share some, but not all, defining mutations of the VOC P.1. For instance, it has the previously described ORF1a:D2980H and N:P383 L unique mutations and the newly detected ORF1a:P1213 L and ORF1b:K2340N mutations. Additionally, a new mutation (E661D) in the spike (S) protein has been identified in nearly 10% of the genomes classified as the VOC P.1 from Parana in March and April 2021. We also report the identification of the S:W152C mutation in one genome from Parana, classified as the N.10 variant. Finally, we analyzed the correlation between the lineage and the P.1 variant frequency, age group (patients younger or older than 60 years old) and the clinical data of 86 cases from the state of Parana. This analysis does not support an association between the P.1 variant prevalence and COVID-19 severity or age strata. Our results provided a reliable picture of the evolution of the SARS-CoV-2 pandemic in the state of Parana characterized by the dominance of the P.1 strain, as well as a high frequencies of the P.1-like-II lineage and the S:E661D mutations. Epidemiological and genomic surveillance efforts should be continued to unveil the biological relevance of the novel mutations detected in the VOC P.1 in Parana.

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