1. MEASUREMENT OF VACCINE EFFICACY AND COVID-19 RISK PROBABILITY ; Defriman Djafri. 2. RELATIONSHIP OF SMOKING RISK FACTORS AND COMORBIDS WITH COVID-19 MORTALITY: SYSTEMATIC REVIEW AND META-ANALYSIS ; Imraatul Hasni, Dien Gusta Anggraini Nursal, Yessy Markolinda, Masrizal Masrizal, Yusmayanti Yusmayanti. 3. MORTALITY ANALYSIS OF COVID-19 IN THE PROVINCE OF WEST SUMATERA ; Nindi Elfiza, …