ABSTRACT
This study sequenced 1077 SARS-CoV-2 genomes from patient isolates (106 from arriving travellers and 971 from communities) to track the molecular evolution and spatio-temporal dynamics of the SARS-CoV-2 variants in Ghana. The data show that initial local transmission was dominated by B.1.1 lineages, but the second wave in Ghana was overwhelmingly driven by the Alpha variant, which was detected in community cases from January 2021, with Eta also contributing to reported cases. Subsequently, an unheralded variant under monitoring, B.1.1.318, dominated transmission from April to June 2021 before being displaced by Delta (B.1.1.617) and Delta Plus (AY.*) variants, which were introduced into community transmission in May 2021 and have remained dominant to date. Mutational analysis indicated that variants that took hold in Ghana harboured transmission enhancing and immune escape spike substitutions. The apparent rapid viral evolution observed demonstrate the potential for emergence of novel variants with greater mutational fitness.
Subject(s)
COVID-19ABSTRACT
The progression of the SARS-CoV-2 pandemic in Africa has so far been heterogeneous and the full impact is not yet well understood. Here, 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 following 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 breeding ground for new variants.