Vietnam's health ministry said on Saturday up to 800,000 visitors to Danang city, the country's new novel coronavirus epicentre, have left for other parts of the country since July 1.
Vietnam last week detected its first locally transmitted Covid-19 cases in more than three months in Danang, a tourism hot spot.
The total number of infections in the country has since risen to 558 from 413, with most of the new cases linked to three hospitals in Danang.
More than 41,000 people have visited the three hospitals since July 1, the ministry said in a statement.
The Southeast Asian country reported its first two Covid-19 deaths on Friday, and the toll rose to three on Saturday.