ABSTRACT
Previous studies have linked the evolution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic variants to persistent infections in people with immunocompromising conditions1-4, but the evolutionary processes underlying these observations are incompletely understood. Here we used high-throughput, single-genome amplification and sequencing (HT-SGS) to obtain up to [~]103 SARS-CoV-2 spike gene sequences in each of 184 respiratory samples from 22 people with HIV (PWH) and 25 people without HIV (PWOH). Twelve of 22 PWH had advanced HIV infection, defined by peripheral blood CD4 T cell counts (i.e., CD4 counts) <200 cells/L. In PWOH and PWH with CD4 counts [≥]200 cells/L, most single-genome spike sequences in each person matched one haplotype that predominated throughout the infection. By contrast, people with advanced HIV showed elevated intra-host spike diversity with a median of 46 haplotypes per person (IQR 14-114). Higher intra-host spike diversity immediately after COVID-19 symptom onset predicted longer SARS-CoV-2 RNA shedding among PWH, and intra-host spike diversity at this timepoint was significantly higher in people with advanced HIV than in PWOH. Composition of spike sequence populations in people with advanced HIV fluctuated rapidly over time, with founder sequences often replaced by groups of new haplotypes. These population-level changes were associated with a high total burden of intra-host mutations and positive selection at functionally important residues. In several cases, delayed emergence of detectable serum binding to spike was associated with positive selection for presumptive antibody-escape mutations. Taken together, our findings show remarkable intra-host genetic diversity of SARS-CoV-2 in advanced HIV infection and suggest that adaptive intra-host SARS-CoV-2 evolution in this setting may contribute to the emergence of new variants of concern (VOCs).
Subject(s)
Coronavirus Infections , HIV Infections , COVID-19ABSTRACT
Viral sequencing has been critical in the COVID-19 pandemic response, but sequencing and bioinformatics capacity remain inconsistent. To examine the utility of a cloud-based sequencing analysis platform for SARS-CoV-2 sequencing, we conducted a cross-sectional study incorporating seven countries in July 2022. Sites submitted sequential SARS-CoV-2 sequences over two weeks to the Global Pathogen Analysis Service (GPAS). The GPAS bioinformatics cloud platform performs sequence assembly plus lineage and related sample identification. Users can share information with collaborators while retaining data ownership. Seven sites contributed sequencing reads from 5,346 clinical samples, of which 4,799/5,346 (89.8%) had a lineage identified. Omicron lineages dominated, with the vast majority being BA.5, BA.4 and BA.2, commensurate with contemporary genomic epidemiological observations. Phylogenetic analysis demonstrated low within-lineage diversity, and highly similar sequences present in globally disparate sites. A cloud-based analysis platform like GPAS addresses bioinformatics bottlenecks and facilitates collaboration in pathogen surveillance, enhancing epidemic and pandemic preparedness.
Subject(s)
COVID-19ABSTRACT
Omicron BA.2.86 subvariant differs from Omicron BA.2 as well as recently circulating variants by over 30 mutations in the spike protein alone. Here we report on the first isolation of the live BA.2.86 subvariant from a diagnostic swab collected in South Africa which we tested for escape from neutralizing antibodies and viral replication properties in cell culture. BA.2.86 did not have significantly more escape than Omicron XBB.1.5 from neutralizing immunity elicited by infection of Omicron subvariants ranging from BA.1 to XBB, either by infection alone or as breakthrough infection in vaccinated individuals. Neutralization escape was present relative to earlier strains: BA.2.86 showed extensive escape both relative to ancestral virus in sera from pre-Omicron vaccinated individuals and relative to Omicron BA.1 in sera from Omicron BA.1 infected individuals. We did not observe substantial differences in viral properties in cell culture relative to XBB.1.5. Both BA.2.86 and XBB.1.5 produced infection foci of similar size, had similar cytopathic effect (both lower than ancestral SARS-CoV-2), and had similar replication dynamics. We also investigated the relationship of BA.2.86 to BA.2 sequences and found that the closest were BA.2 samples from Southern Africa circulating in early 2022. These observations suggest that BA.2.86 is more closely related to sequences from Southern Africa than other regions and so may have evolved there, and that evolution led to escape from neutralizing antibodies similar in scale to recently circulating strains of SARS-CoV-2.
Subject(s)
Breakthrough PainABSTRACT
South Africa's fourth COVID-19 wave was driven predominantly by three lineages (BA.1, BA.2 and BA.3) of the SARS-CoV-2 Omicron variant of concern. We have now identified two new lineages, BA.4 and BA.5. The spike proteins of BA.4 and BA.5 are identical, and comparable to BA.2 except for the addition of 69-70del, L452R, F486V and the wild type amino acid at Q493. The 69-70 deletion in spike allows these lineages to be identified by the proxy marker of S-gene target failure with the TaqPath COVID-19 qPCR assay. BA.4 and BA.5 have rapidly replaced BA.2, reaching more than 50% of sequenced cases in South Africa from the first week of April 2022 onwards. Using a multinomial logistic regression model, we estimate growth advantages for BA.4 and BA.5 of 0.08 (95% CI: 0.07 - 0.09) and 0.12 (95% CI: 0.09 - 0.15) per day respectively over BA.2 in South Africa.