The two patients, both women, were treated at the National Hospital of Tropical Diseases.

One of them is a 44-year-old woman who works for the Truong Sinh Company, which provides food and logistic services for several Hanoi hospitals, including the Bach Mai Hospital, which had become a major outbreak site.

She is a relapse case who was first confirmed infected on March 29 before being discharged on April 16, then found to have relapsed on April 18.

The other patient is a 60-year-old woman from Ha Loi Village, another major outbreak site. She was confirmed infected on April 13.

"I cried all the time, because I’d neither fallen sick nor made contact with anyone. Even those who were infected with Covid-19 were several hundred meters away from my house, then why did I get infected?" she recalled, expressing happiness on being told she has recovered.

Vietnam has confirmed 324 Covid-19 cases so far and has recorded no community transmission for over a month.

The country’s most seriously ill Covid-19 patient, a 43-year-old British man designated as "Patient 91," was announced free of the novel coronavirus Wednesday morning. However, his condition remains critical and he is on life support.

Doctors said Thursday said they were trying to help the patient breathe with his own lungs by gradually making him less dependent on the extracorporeal membrane oxygenation (ECMO) machine. His lungs are now 30 percent functional, compared to 10 percent a week earlier.

"The patient’s lungs are getting better, so ECMO stats are being gradually reduced so the patient can practice breathing with his own lungs," said Nguyen Van Vinh Chau, director of the HCMC Hospital for Tropical Diseases, where the patient is being treated.

Reducing ECMO stats means reducing blood flow speed and oxygenation levels facilitated by the technique, allowing the lungs to play a bigger role in oxygenation. Once the stats have gotten low enough and oxygenation levels are still fine, the patient can stop relying on ECMO, said Chau.

The Health Ministry had earlier announced a decision to give "Patient 91" a lung transplant. It planned to transfer him to Cho Ray Hospital for further treatment and even back to the U.K. when he's well enough to fly.