Among the new patients, the 21-year-old woman from the US had transited the Republic of Korea before boarding Flight VN431 that arrived at Da Nang Airport in central Da Nang city on November 23, said the National Steering Committee for COVID-19 Prevention and Control.
Another woman, 22, entered the country via Noi Bai Airport in Hanoi on Flight VJ7837 from Japan on November 27.
Meanwhile, the 25-year-old man returned from Japan on Flight QH4913 to Noi Bai Airport on November 28.
All of them have been quarantined upon arrival.
There have been 1,179 recoveries from COVID-19 in the country so far.
Six of those still under treatment have tested negative for the coronavirus once, seven others twice, and 12 thrice.
The number of related deaths is still kept at 35 while no patients are in critical condition at present, according to the sub-committee for treatment.
As many as 16,204 people having close contact with confirmed cases or coming from pandemic-hit regions are under quarantine now, including 179 in hospitals, 15,149 in other quarantine sites, and 876 at home or accommodation facilities.