Persistent SARS-COV-2 infection in vaccinated individual with three doses of COVID-19 vaccine.

We describe a case of a 24-year-old Brazilian woman previously vaccinated with CoronaVac and a booster dose of Pfizer-BioNTech, with mild-to-moderate COVID-19, with persistent viral shedding. We evaluated viral load, antibody dynamics for SARS-CoV-2 and performed genomic analysis to identify the viral variant. The female remained positive for 40 days following symptom onset (cycle quantification mean: 32.54 ± 2.29). The humoral response was characterized by absence of IgM for the viral spike protein, increased IgG for the viral spike (1800.60 to 19558.60 AU/mL) and for the nucleocapsid (from 0.03 to 8.9 index value) proteins, and high titers of neutralizing antibodies (>488.00 IU/mL). The variant identified was the sublineage BA. 5.1. of Omicron (B.1.1.529). Our results suggest that even though the female produced an antibody response against SARS-CoV-2, the persistent infection can be explained by antibody decline and/or the immune evasion by the Omicron variant, illustrating the need to revaccinate or update vaccines.

New 5-carba-pterocarpans: Synthesis and preliminary antiproliferative activity on a panel of human cancer cells.

Natural pterocarpans and synthetic 5-carba-pterocarpans are isosteres in which the oxygen atom at position 5 in the pyran-ring of pterocarpans is replaced by a methylene group. These 5-carba-analogues were obtained in good yields through the palladium-catalyzed oxyarylation of alcoxy-1,2-dihydronaphthalens with o-iodophenols in PEG-400. They were evaluated on human cancer cell lineages derived respectively from prostate tumor (PC3, IC50 = 11.84 µmol L-1, SI > 12)) and acute myeloid leukemia (HL-60, IC50 = 8.81 µmol L-1, SI > 16), highly incident cancer types presenting resistance against traditional chemotherapeutics. Compound 6c (LQB-492) was the most potent (IC50 = 3.85 µmol L-1, SI > 37) in SF-295 cell lineage (glioblastoma). Such findings suggest that 5-carba-pterocarpan can potentially be new hit compounds for further development of novel antiproliferative agents.