Study for the effect of traditional Chinese medicine Intervention among the high-risk population of close contacts of COVID-19 cases

INTERVENTION: Experimental group:The treatment group is provided general care measures + traditional Chinese herbs intervention prescription in the first 5 days, and isolated at home in the next 5 days without taking traditional Chinese herbs.;Control group:The control group is only provided general care measures within 5 days without taking Chinese herbs; CONDITION: Corona Virus Disease 2019 (COVID‐19) PRIMARY OUTCOME: Positive rate; SECONDARY OUTCOME: Viral loan;Median time of virus negative;fever;vomit;headache;cough;fatigue;dry throat;sore throat;stuffy nose;runny nose;poor appetite;sleep; INCLUSION CRITERIA: 1. Close contacts of COVID‐19 living in the isolation point and high‐risk groups exposed together (hereinafter referred to as "contacts"); 2. Age >= 18 years old; 3. Those who agree to participate in the study and sign the informed consent.