The critical patient, Le Tuyet Hang, was admitted to Hanoi’s National Hospital of Tropical Diseases for Covid-19 treatment on March 7. She has undergone the longest treatment of all novel coronavirus infections recorded so far in the country, at more than 80 days, and has been one of its most critical cases.

For 17 days she became full reliant on the life support machine called Extracorporeal membrane oxygenation (ECMO) that allows her lungs and hearts to function properly.

Her heart suddenly stopped one night on April 7, forcing doctors to defibrillate her and perform other emergency procedures continuously for 40 minutes.

Hang was infected by her 26-year-old niece, Nguyen Hong Nhung, who was confirmed positive with Covid-19 on March 6, four days after she returned to Hanoi from London. Nhung’s case ended Vietnam’s 22-day streak of no new Covid-19 infection at the time

By Tuesday, Hang had tested negative seven times. Now she is in stable condition and can walk by herself, something she found very difficult to do two weeks ago.

"Though she has recovered from Covid-19 and been able to breathe and walk normally, the virus has caused a lot of damage to her body and she still has to take a lot of medicine," said Vu Dinh Phu, head of the hospital’s resuscitation department.

The cost for treating Hang has been estimated at VND2-3 billion ($85,700-126,600). All Vietnamese citizens having Covid-19 are treated for free.

Nguyen Van Kinh, head of the board in charge of treating Covid-19 patients at the Health Ministry, said the recovery of Hang was a "remarkable feat."

"On seeing that she has beaten the disease and cheated death, all doctors and I are over the moon," he said.

Luu Ngoc, 40, Hang’s son, said he and his brother had been "extremely worried and scared."

"Her heart used to stop and we were desperate. We've counted on the doctors every day for our mother to overcome the disease," he said.

The day his mother came out of a coma, Ngoc and his brother asked Hang if she could recognize them. As she nodded, the two felt huge relief.

"Thanks to the care and treatment of doctors and nurses, our mother is much better. We have been under a lot of strain," Ngoc said.

Among the other five cases confirmed to have recovered Wednesday, four are Vietnamese returning from abroad via repatriation flights and one a relapse case.

Of the returnees, three had returned from Russia on May 13 and the other returned from the U.S. on May 16.

All recovered patients will be monitored at the hospital for another 14 more days.

Vietnam now has 49 active Covid-19 patients, 278 of the total 327 cases recorded so far having recovered.