Scientifically accurate atomic model of the external structure of the SARS-CoV-2. Each "ball" is an atom. Published by N+1.Credit: William Warby
A new study published in Nature Communications into the spread of coronavirus variants in Nigeria, showed that inequality in SARS-CoV-2 genomic surveillance delays the detection of globally significant variants of concern (VOC).
Researchers have been sequencing the genomes of coronaviruses in patients to spot and stop variant outbreaks before they fuel a new wave of infections. But surveillance through genomic sequencing has been uneven , with many countries in Africa lacking sequencing capacity for SARS-CoV-2.
Olubusuyi Adewumi, a virologist at the College of Medicine, University of Ibadan, Nigeria, in collaboration with colleagues at Northwestern University Feinberg School of Medicine, in Chicago, USA, sequenced and analysed 378 SARS-CoV-2 genomes from samples collected from people infected with COVID-19 in Oyo state, southwestern Nigeria, between July 2020 and August 2021.
The analysis found that in early 2021, about 89% of variants were the Alpha VOC, and the Eta variant. The Eta variant, however, outcompeted Alpha in Nigeria and across West Africa, and persisted in the region even after the arrival of the rarer Delta VOC. The study also found that spike protein from the Eta variant conferred increased infectivity and decreased neutralization by convalescent sera in vitro.
The researchers suggest that Eta could have been designated as a VOC had it been detected earlier, given its ability to outcompete Alpha in West Africa, and the evidence of increased infectivity and enhanced immune evasion after natural infection.
“This research gave us the opportunity to understand the circulating variants in Nigeria, and paint a picture of what’s happening in the country,” Adewumi told Nature Africa. “It underscores the need for improved genomic sequencing in under-sampled countries.”
