Hanoi remained the largest coronavirus hotspot with 347 cases, followed by Bac Ninh (138) and Vinh Phuc (90).
The national tally now reached 10,708,887.
Over 8,940 COVID-19 patients were given the all clear on the day, bringing the number of recoveries so far to 9,402,046.
A total of 211 patients are currently given breathing support. No deaths were recorded in the past 24 hours, keeping the fatalities at 43,075..
By May 21, the country had injected 219,084,118 doses of COVID-19 vaccines, including 3,406,264 first doses and 24,272 second doses for children from five to under 12 years old.