This is a randomized, blank-controlled study in adults with household contact exposure to individuals with SARS-CoV-2 infection. All subjects in the study will be household contacts with close exposure to the first household member known to be newly infected with SARS-CoV-2. Subjects in each cohort will be randomly assigned to the Chinese herbal medicine treatment group or blank control group in a 4:1 ratio, followed by 1 week of the treatment period and 2 weeks of follow-up.

Inclusion Criteria:

1. Household contact exposure to individuals with SARS-CoV-2 infection
2. Aged ≥18
3. General healthy or have a chronic, stable medical condition
4. Voluntarily signing a written informed consent form
5. Able to follow written and oral instructions in Chinese

Exclusion Criteria:

1. Moderate to severe symptomatic SARS-CoV-2 infection
2. An allergic history to Chinese herbal drugs or a known allergy to the ingredients of the study drug
3. Pregnancy, breastfeeding or plan to become pregnant within the study timeframe
4. Vulnerable adults (i.e., mentally or physically disabled to take care of himself/herself)
5. Any physical examination findings, and/or history of any illness, or concomitant medications that, in the opinion of the study investigator, might not be suitable to participate in the study

All the individual participant data that underlie the results reported in the published article will be shared after de-identification.

Beginning 3 months and ending 5 years following article publication

Researchers who provide a methodologically sound proposal