A prospective, randomized, open-label, controlled clinical study to evaluate the preventive effect of hydroxychloroquine on close contacts after exposure to the Novel Coronavirus Pneumonia (COVID-19)

INTERVENTION: A1:Hydroxychloroquine, small dose;A2:Hydroxychloroquine, high dose;B1:Abidol hydrochloride, small dose;B2:Abidol hydrochloride, high dose; CONDITION: Novel Coronavirus Pneumonia (COVID‐19) PRIMARY OUTCOME: Number of patients who have progressed to suspected or confirmed within 24 days of exposure to new coronavirus; SECONDARY OUTCOME: Clinical manifestations and severity of suspected or confirmed patients;Body temperature;Cough severity classification;Oxygenation index;Chest CT lesion size;Incidence of severe adverse drug reactions;Blood routine, CRP, SAA values; INCLUSION CRITERIA: 1. 18 years old <= age <= 60 years old when screening, not limited to men and women; 2. Who are in close contact with suspected cases, confirmed cases, and positive test of new coronavirus nucleic acid, and those who have not taken effective protection, that is, close contacts; 3. Study subjects are willing to be randomly assigned to any designated treatment group; 4. Must agree to not participate in another study of study drugs until day 24 of completion of the study. 5. Participants volunteered to participate in this study and signed informed consent.