- Participants were excluded if meet one or more of following criteria: were or were at risk of immunodeficiency, severe allergic reaction, acute fever and infectious diseases, severe chronic diseases, family history of allergies, convulsions, seizures, encephalopathy and psychiatric diseases, oral steroids at least 14 consecutive days in the past month, axillary temperature equal or greater than 38·0°C in the past three days, diarrhea (defection frequency equal or greater than three times per day) in the past seven days, and participated in other drug clinical trials.