BBIBP-CorV vaccination accelerates anti-viral antibody responses in heterologous Omicron infection: A retrospective observation study in Shanghai.

OBJECTIVES: To investigate how BBIBP-CorV vaccination affecting antibody responses upon heterologous Omicron infection. METHODS: 440 Omicron-infected patients were recruited in this study. Antibodies targeting SARS-CoV-2 spike protein receptor binding domain (RBD) and nucleoprotein of both wild-type (WT) and Omicron were detected by ELISA. The clinical relevance was further analyzed. RESULTS: BBIBP-CorV vaccinated patients exhibited higher anti-RBD IgG levels targeting both WT and Omicron than non-vaccinated patients at different stages. By using a 3-day moving average analysis, we found that BBIBP-CorV vaccinated patients exhibited the increases in both anti-WT and Omicron RBD IgG from the onset and reached the plateau at Day 8 whereas those in non-vaccinated patients remained low during the disease. Significant increase in anti-WT RBD IgA was observed only in vaccinated patients. anti-Omicron RBD IgA levels remained low in both vaccinated and non-vaccinated patients. Clinically, severe COVID-19 only occurred in non-vaccinated group. anti-RBD IgG and IgA targeting both WT and Omicron were negatively correlated with virus load, hospitalization days and virus elimination in vaccinated patients. CONCLUSIONS: BBIBP-CorV vaccination effectively reduces the severity of Omicron infected patients. The existence of humoral memory responses established through BBIBP-CorV vaccination facilitates to induce rapid recall antibody responses when encountering SARS-CoV-2 variant infection.

Phenolic glycoside constituents from Brassica rapa flowers and their α-glucosidase inhibitory activity.

Two new phenolic glycoside compounds (1, 2) and ten known analogues (3-12) have been isolated from the ethanolic extract of Brassica rapa flowers and identified as 2-O-ß-d-glucopyranosyl-(1S)-(4-methoxyphenyl)ethylene glycol (1), 2-(4-O-ß-d-allopyranosyl)phenyl-ethanol (2), 2-O-ß-d-glucopyranosyl-(1S)-phenylethylene glycol (3), 2-O-ß-d-glucopyranosyl-(1R)-phenylethylene glycol (4), (Z)-p-coumaryl-O-ß-d-glucopyranoside (5), phenyl-O-ß-d-glucopyranoside (6), 2-phenylethyl-O-ß-d-glucopyranoside (7), salidroside (8), 2-(2-hydroxyphenyl)ethanol-O-ß-d-glucopyranoside (9), 4-methoxybenzyl-O-ß-d-glucopyranoside (10), 2,4,6-trimethoxyphenyl-1-O-ß-d-glucopyranoside (11) and sachaliside 1 (12). The structures of 1 and 2, including absolute configurations, were determined by spectroscopic data (1H NMR, 13C NMR, HSQC, HMBC and ORD) and chemical methods. In addition, most of them exhibited inhibitory activity with IC50 values ranging from 14.43 to 50.20 µM in comparison to the positive control acarbose (IC50 = 15.76 µM) in intestinal α-glucosidase inhibitory activity tests.