Most of the new cases were detected in Hanoi, at 7,419, followed by the northern provinces of Bac Giang (2,998 cases) and Hai Duong (2,944).
The average single-day cases nationwide in the last seven days was 47,264.
In the past 24 hours, 91 Covid-19 patients have died, including 11 in Hanoi.
Since the pandemic started in 2020, the death toll in Vietnam has climbed to 39,719 or 1.3 percent of all infections.
In the latest wave that hit the country in late April, more than 2.9 million cases have been confirmed and 2.3 million of them have recovered.
So far, 78.7 percent of the population have received two vaccine doses.