Rapid dynamic changes of FL.2 variant: A case report of COVID-19 breakthrough infection.

We investigated intra-host genetic evolution using two SARS-CoV-2 isolates from a fully vaccinated (primary schedule x2 doses of AstraZeneca plus a booster of Pfizer), >70-year-old woman with a history of lymphoma and hypertension who presented a SARS-CoV-2 infection for 3 weeks prior to death due to COVID-19. Two full genome sequences were determined from samples taken 13 days apart with both belonging to Pango lineage FL.2: the first detection of this Omicron sub-variant in Botswana. FL.2 is a sub-lineage of XBB.1.9.1. The repertoire of mutations and minority variants in the Spike protein differed between the two time points. Notably, we also observed deletions within the ORF1a and Membrane proteins; both regions are associated with high T-cell epitope density. The internal milieu of immune-suppressed individuals may accelerate SARS-CoV-2 evolution; hence, close monitoring is warranted.

Fostemsavir resistance-associated polymorphisms in HIV-1 subtype C in a large cohort of treatment-naïve and treatment-experienced individuals in Botswana.

IMPORTANCE: Fostemsavir (FTR) is a newly licensed antiretroviral drug that has been shown to have activity against HIV-1. The mechanism of action of FTR is different from all currently available antiretrovirals (ARVs), and as such, it offers hope for HIV-1 suppression in those people with HIV (PWH) who harbor HIV-1 variants with drug resistance mutations to currently used ARVs. Using 6,030 HIV-1 sequences covering the HIV-1 envelope from PWH in Botswana who are antiretroviral therapy (ART) naïve as well as those who are failing ART, we explored the sequences for FTR resistance-associated polymorphisms. We found the prevalence of FTR polymorphisms to be similar in both ART-naïve and ART-experienced individuals with VF in this setting, with no prior FTR exposure. Further studies on the phenotypic impact of these polymorphisms are warranted to guide how to monitor for FTR resistance.