A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa.

The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants.

Implications of SARS-CoV-2 genetic diversity and mutations on pathogenicity of the COVID-19 and biomedical interventions.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) has caused an unprecedented global health emergency. The COVID-19 pandemic has claimed over 350,000 human lives within five months of its emergence, especially in the USA and the European continent. This study analysed the implications of the genetic diversity and mutations in SARS-CoV-2 on its virulence diversity and investigated how these factors could affect the successful development and application of antiviral chemotherapy and serodiagnostic test kits, and vaccination. METHODS: All the suitable and eligible full text articles published between 31st December 2019 and 31st May 2020 were filtered and extracted from "PubMed", "Scopus", "Web of Science", and "Hinari" and were critically reviewed. We used the Medical Subject Headings (MeSH) terms "COVID-19, "Mutation", "Genetic diversity", "SARS-CoV-2", "Virulence", "Pathogenicity", "Evolution" and "SARS-CoV-2 transmission" for this search. RESULTS: Our search showed that SARS-CoV-2 has persistently undergone significant mutations in various parts of its non-structural proteins (NSPs) especially NSP2 and NSP3, S protein, and RNA-dependent RNA polymerase (RdRp). In particular, the S protein was found to be the key determinant of evolution, transmission, and virulence of SARS-CoV-2, and could be a potential target for vaccine development. Additionally, RdRp could be a major target in the development of antivirals for the treatment of COVID-19. CONCLUSION: Given the critical importance of mutations in the pathogenicity of SARS-CoV-2 and in the development of sero-diagnostics, antivirals, and vaccines, this study recommends continuous molecular surveillance of SARS-CoV-2. This approach would potentially prompt identification of new mutants and their impact on ongoing biomedical interventions and COVID-19 control measures.