Three patients, aged 25, 29 and 30, were admitted to the National Hospital for Tropical Diseases in Hanoi on May 18. They were announced Covid-19 free on Friday morning after each tested negative twice.

Two others were treated at the Tropical Diseases Hospital of the nearby Hai Duong Province.

Together, they returned to Vietnam on May 13 via Vietnam Airlines flight VN0062, a repatriation initiative organized by the government. A total 34 people on the flight were later found positive for the coronavirus, including two male attendants. Earlier, 12 infected people from the flight have recovered.

Doctor Tran Hai Ninh of the Hanoi hospital said the three patients had suffered damage to their lungs but did not experience breathing difficulties or respiratory failure.

One had to use an oxygen mask during treatment, though his condition did not worsen.

The five will remain under monitor at the hospitals for 14 more days.

The National Hospital for Tropical Diseases now has 12 Covid-19 patients left while the Hai Duong hospital has one left, a one-year-old boy on the same flight.

Nationwide, 21 are in still hospitals for the disease.

Vietnam has recorded 328 cases of Covid-19, as last updated on the morning of May 30. Aside from those active, the rest have all recovered.

Friday morning marked day 50 without Vietnam recording any community transmission.

The country’s most seriously ill Covid-19 patient, a British pilot for national carrier Vietnam Airlines, has regained 58 percent in lung function, compared to 40 percent a week ago and just 10 percent three weeks prior.

"Patient 91," as he was designated, was disconnected from the extracorporeal membrane oxygenation (ECMO), a life support system on Wednesday after 57 days, following signs of recovery. Yet his condition remains critical due to lung infection.