The three localities with the highest number of new cases were Ho Chi Minh City with 1,491 cases, Can Tho with 1,132 and Tay Ninh with 792 cases.
Hanoi recorded 400 new cases on Sunday
The Covid-19 death toll in Vietnam rose to 26,220 with the confirmation of 199 deaths on Sunday.
Health authorities also confirmed 1,711 recoveries the same day, bringing the total tally of recovered cases so far to 1,009,277.
Almost 54.1 million people of the nation's 96-million population have been fully vaccinated.