All the patients are Vietnamese citizens living in Hanoi, Ho Chi Minh City, and three provinces of Gia Lai, Thanh Hoa and Phu Tho.
They have twice tested negative for the SARS-CoV-2 virus that causes the COVID-19 disease.
The patients are in stable health condition and show no signs of virus symptoms such as a high temperature, a cough or shortness of breath.
They will be placed in quarantine for another 14 days according to regulations on COVID-19 prevention and control.
As of July 21, Vietnam has recorded a total of 396 coronavirus cases of which 365 cases have fully recovered from the disease.
The country has also gone more than three months without new locally transmitted infections.
