Reduced SARS-CoV-2 infection risk is associated with the use of Seven-Flavor Herb Tea: A multi-center observational study in Shanghai, China

Objective: Omicron, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, is responsible for numerous infections in China. This study investigates the association between the use of Seven-Flavor Herb Tea (SFHT) and the risk of SARS-CoV-2 infection to develop precise and differentiated strategies for control of the coronavirus disease 2019 (COVID-19). Methods: This case-control study was conducted at shelter hospitals and quarantine hotels in China. A total of 5348 laboratory-confirmed COVID-19 patients were enrolled between April 1 and May 31, 2022, while 2190 uninfected individuals served as healthy controls. Structured questionnaires were used to collect data on demographics, underlying diseases, vaccination status, and use of SFHT. Patients were propensity-score-matched using 1:1 nearest-neighbor matching of the logit of the propensity score. Subsequently, a conditional logistic regression model was used for data analysis. Results: Overall, 7538 eligible subjects were recruited, with an average age of [45.54 +/- 16.94] years. The age of COVID-19 patients was significantly higher than that of uninfected individuals ([48.25 +/- 17.48] years vs [38.92 +/- 13.41] years; t = 22.437, P < 0.001). A total of 2190 COVID-19 cases were matched with uninfected individuals at a 1:1 ratio. The use of SFHT (odds ratio = 0.753, 95% confidence interval: 0.692, 0.820) was associated with a lower risk of SARS-CoV-2 infection compared to untreated individuals. Conclusion: Our findings suggest that taking SFHT reduces the risk of SARS-CoV-2 infection. This is a useful study in the larger picture of COVID-19 management, but data from large-sample multi-center, randomized clinical trial are warranted to confirm the finding. (C) 2023 Shanghai Yueyang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).