He said Tuesday that the Tet break, which lasted from Jan. 29 to Feb. 6, came at a time when cities and provinces across the country had resumed almost all socio-economic activities.
During the period many people returned to their hometowns or toured, posing a high risk of spread of the virus, especially the Omicron strain, which is more contagious than previous strains, including the Delta, he said.
"More hospitalizations are likely to be next, putting great pressure on the healthcare system."
The number of cases has been on the rise in recent days, going up from 11,500 on Feb. 4 to 12,160, 14,100, 16,800, and 21,900 the next four days.
Experts had warned there would be an increase after Tet, but say the situation is "not yet worrisome" and all that needs to be done now is to follow the health ministry's safety guidance.
Tran Dac Phu, a senior advisor to the ministry's Public Health Emergency Operations Center, said, "Though there are more cases the pandemic situation is still under control."
This is because not many cases are severe thanks to the high vaccination rate.
Over 74 million out of Vietnam's 96 million people have received two doses, and 30 million have also received the third.
Do Van Dung, head of the Public Health department of the HCMC University of Medicine and Pharmacy, said given the current vaccination rate, if people strictly comply with the Covid prevention protocols, wearing masks, disinfecting and avoiding gatherings, the number of cases would rise briefly before dropping again, and there would be no new wave.
But the fact remains that there have been severe outbreaks after long holidays.
After Lunar New Year last year the third wave broke out with more than 1,300 cases in 13 provinces and cities.
After the Reunification Day and Labor Day holidays from April 30 to May 5 last year the deadly fourth wave broke out, and Vietnam was battered by a combination of the Delta variation and low vaccination rate. The number of infections has topped 2.3 million, with 38,489 people succumbing to it.
Nguyen Tien Dung, former head of the pediatrics department at Bach Mai, one of Hanoi's top hospitals, has a completely different opinion.
He said people should now treat Covid like a normal disease and should not worry too much if they get infected.
"Covid-19 is not as scary as it used to be, and most people can treat themselves at home."
But it is necessary to report to authorities if someone contracts the disease to avoid spreading it widely, he admitted.