Real-world experience of Fuzheng Yiqing granule as chemoprophylaxis against COVID-19 infection among close contacts: A prospective cohort study

Background: The objective of the current study was to evaluate whether the use of traditional Chinese medicine, Fuzheng Yiqing granule (FZYQG), was associated with a reduced infection risk of COVID-19 in close contacts. Research design and methods: This was a prospective cohort study across 203 quarantine centres for close contacts and secondary contacts of COVID-19 patients in Yangzhou city. FZYQG group was defined as quarantined individuals who voluntarily took FZYQG; control group did not take FZYQG. The primary outcome was the coronavirus test positive rate during quarantine period. Logistic regression with propensity score inverse probability weighting was used for adjusted analysis to evaluate independent association between FZYQG and test positive rate. Results: From July 13, 2021 to September 30, 2021, 3438 quarantined individuals took FZYQG and 2248 refused to take the granule. Test positive rate was significantly lower among quarantined individuals who took FZYQG (0.29% vs. 1.73%, risk ratio 0.17, 95% confidence interval (CI): 0.08-0.34, p < 0.001). On logistic regression, odds for test positive were decreased in FZYQG group (odds ratio: 0.16, 95% CI: 0.08-0.32, p < 0.001). Conclusions: Close and secondary contacts of COVID-19 patients who received FZYQG had a lower test positive rate than control individuals in real-world experience.