The trio returned to Vietnam from France on Wednesday and were quarantined upon arriving at Tan Son Nhat International Airport in Ho Chi Minh City.
Vietnam has to date recorded a total of 1,256 imported and locally transmitted COVID-19 cases.
Of the total, 1,101 patients have recovered from the disease, and 35 patients have died of the virus and related illnesses.
Vietnam has gone through 72 consecutive days without detecting a single locally transmitted infection.