The three localities with the highest number of new cases were Hanoi with 3,507 cases, Hai Duong with 1,915 cases, and Hai Phong with 1,489 cases.
Of the day's tally, 20,924 cases were detected in the community.
Vietnam has recorded 198 cases infected with the Omicron variant, with 97 of them in HCMC.
The Covid-19 death toll in Vietnam rose to 39,040 with the confirmation of 91 deaths Monday.
The Health Ministry also confirmed 6,193 recoveries the same day, bringing the total number of recovered cases so far to 2,232,947.
Over 74.7 million people of Vietnam's 96 million population have been vaccinated with two doses, and more than 32 million have received the third dose.