Retrospective Insights of the COVID-19 Epidemic in the Major Latin American City, São Paulo, Southeastern Brazil.

São Paulo is the financial center of Brazil, with a population of over 12 million, that receives travelers from all over the world for business and tourism. It was the first city in Brazil to report a case of COVID-19 that rapidly spread across the city despite the implementation of the restriction measures. Despite many reports, much is still unknown regarding the genomic diversity and transmission dynamics of this virus in the city of São Paulo. Thus, in this study, we provide a retrospective overview of the COVID-19 epidemic in São Paulo City, Southeastern, Brazil, by generating a total of 9995 near-complete genome sequences from all the city's different macro-regions (North, West, Central, East, South, and Southeast). Our analysis revealed that multiple independent introduction events of different variants (mainly Gamma, Delta, and Omicron) occurred throughout time. Additionally, our estimates of viral movement within the different macro-regions further suggested that the East and the Southeast regions were the largest contributors to the Gamma and Delta viral exchanges to other regions. Meanwhile, the North region had a higher contribution to the dispersion of the Omicron variant. Together, our results reinforce the importance of increasing SARS-CoV-2 genomic monitoring within the city and the country to track the real-time evolution of the virus and to detect earlier any eventual emergency of new variants of concern that could undermine the fight against COVID-19 in Brazil and worldwide.

The Divergent Pattern of SARS-CoV-2 Variant Predominance and Transmission Dynamics in the Brazilian Island of Ilhabela.

Our effort in SARS-CoV-2 genomic surveillance in Brazil has detected the Alpha Variant of Concern with a predominance higher than 75% in the population of Ilhabela island (São Paulo State) at a time when the Gamma VOC was already predominating the mainland raised concerns for closer surveillance on this island. Therefore, we intensified the surveillance for 24 weeks by generating data from 34% of local positive cases. Our data show that the patterns of VOC predominance dynamics and infection rates were in general distinct from the mainland. We report here the first known case of Alpha predominance in a Brazilian population, a delay greater than 3 months for the Gamma to dominate the previous variants compared to the mainland, and a faster dispersion rate of Gamma and Delta VOCs compared to the mainland. Phylogenetic analysis revealed the SARS-CoV-2 transmission dynamics in Ilhabela were characterized by multiple independent introduction events of Gamma and Delta, with a few events of Alpha introduction, two of them followed by community transmission. This study evidenced the peculiar behavior of SARS-CoV-2 variants in an isolated population and brought to light the importance of specific programs for SARS-CoV-2 genomic surveillance in isolated populations.

SARS-COV-2 genomic monitoring in the state of São Paulo unveils two emerging AY.43 sublineages.

Delta VOC is highly diverse with more than 120 sublineages already described as of November 30, 2021. In this study, through active monitoring of circulating severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants in the state of São Paulo, southeast Brazil, we identified two emerging sublineages from the ancestral AY.43 strain which were classified as AY.43.1 and AY.43.2. These sublineages were defined by the following characteristic nonsynonymous mutations ORF1ab:A4133V and ORF3a:T14I for the AY.43.1 and ORF1ab:G1155C for the AY.43.2 and our analysis reveals that they might have a likely-Brazilian origin. Much is still unknown regarding their dissemination in the state of São Paulo and Brazil as well as their potential impact on the ongoing vaccination process. However, the results obtained in this study reinforce the importance of genomic surveillance activity for timely identification of emerging SARS-CoV-2 variants which can impact the ongoing SARS-CoV-2 vaccination and public health policies.

Genomic monitoring of the SARS-CoV-2 B1.1.7 (WHO VOC Alpha) in the Sao Paulo state, Brazil.

The SARS-CoV-2 alpha VOC (also known as lineage B.1.1.7) initially described in the autumn, 2020 in UK, rapidly became the dominant lineage across much of Europe. Despite multiple studies reporting molecular evidence suggestive of its circulation in Brazil, much is still unknown about its genomic diversity in the state of São Paulo, the main Brazilian economic and transportation hub. To get more insight regarding its transmission dynamics into the State we performed phylogenetic analysis on all alpha VOC strains obtained between February and August 2021 from the Sao Paulo state Network for Pandemic Alert of Emerging SARS-CoV-2 variants. The performed phylogenetic analysis showed that most of the alpha VOC genomes were interspersed with viral strains sampled from different Brazilian states and other countries suggesting that multiple independent Alpha VOC introductions from Brazil and overseas have occurred in the São Paulo State over time. Nevertheless, large monophyletic clusters were also observed especially from the Central-West part of the São Paulo State (the city of Bauru) and the metropolitan region of the São Paulo city. Our results highlight the Alpha VOC molecular epidemiology in the São Paulo state and reinforce the need for continued genomic surveillance strategies for the real-time monitoring of potential emerging SARS-CoV-2 variants during the ever-growing vaccination process.

Genomic epidemiology of the SARS-CoV-2 epidemic in Brazil

The high numbers of COVID-19 cases and deaths in Brazil have made Latin America an epicentre of the pandemic. SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, but important gaps remain in our understanding of virus transmission dynamics at a national scale. We use 17,135 near-complete genomes sampled from 27 Brazilian states and bordering country Paraguay. From March to November 2020, we detected co-circulation of multiple viral lineages that were linked to multiple importations (predominantly from Europe). After November 2020, we detected large, local transmission clusters within the country. In the absence of effective restriction measures, the epidemic progressed, and in January 2021 there was emergence and onward spread, both within and abroad, of variants of concern and variants under monitoring, including Gamma (P.1) and Zeta (P.2). We also characterized a genomic overview of the epidemic in Paraguay and detected evidence of importation of SARS-CoV-2 ancestor lineages and variants of concern from Brazil. Our findings show that genomic surveillance in Brazil enabled assessment of the real-time spread of emerging SARS-CoV-2 variants.

SARS-CoV-2 genomic monitoring in the São Paulo State unveils new sublineages of the AY.43 strain

Delta VOC is highly diverse and more than 120 sublineages have been identified in Pango lineages with the continuous description of emerging ones. Brazil is now one of the most vaccinated countries against SARS-CoV-2 in the world which can enhance the emergence of viral mutations related to improved viral fitness. In this study, we identified two novel sublineages of the AY.43 lineage which were classified as AY.43.1 and AY.43.2 as observed on the specific clustering on the obtained phylogenetic tree. The novel sublineages were defined by the following characteristic nonsynonymous mutations ORF1ab:A4133V and ORF3a:T14I for AY.43.1 and ORF1ab:G1155C for AY.43.2. The majority of the analyzed sequences of both lineages were Brazilian, which shows that probably these two emerging sublineages have Brazilian origin. It is still unknown how these two sublineages are disseminated in São Paulo State and Brazil and their potential impact on the ongoing vaccination process. However, the performed study reinforces the importance of the SARS-CoV-2 genome monitoring for timely identification of emerging SARS-CoV-2 variants which can impact the ongoing SARS-CoV-2 vaccination and public health policies.