"I was frightened after contracting the novel coronavirus, but I think I could overcome it because I am young and healthy," the 28-year-old told VnExpress on Friday.
He claimed to have cried when he came to know he was the source of community transmission.
"I felt regretful from the first moment and very repentant as my behavior has affected the whole society."
On hearing he faces criminal charges for violating quarantine regulations and infecting at least three others, he was "very scared and shocked."
Until now people flouting Covid-19 prevention regulations were let off with fines.
He worked on flights to repatriate Vietnamese stuck in France, Australia and the U.K., and said he got many encouraging messages from passengers on those flights while in hospital.
"These words of encouragement helped me feel less heartbroken after being hurt by the viciousness on social media."
He has come under severe criticism on social media, with many blasting him for his lack of awareness.
He said he was fortunate his mother did not contract the coronavirus. During his self-quarantine at home on Bach Dang Street in Tan Binh District, his mother had often brought him food.
He had returned from Japan on November 14, and was quarantined for four days at a Vietnam Airlines facility in Tan Binh District.
But he breached quarantine rules, visiting another quarantine area where he contracted the virus from a colleague who had returned from Romania.
HCMC health officials said this pointed to the lax management of the facility by Vietnam Airlines. Rules prohibit even people who worked on the same flight from coming into contact during the quarantine period.
After two tests for the coronavirus proved negative, he was allowed to go home and isolate himself. But he violated this rule and came into contact with his mother and two friends, including an English language teacher who stayed with him for a few days.
The teacher, and from him a nephew and a student of his, then contracted the virus.
The flight attendant also left home to eat out and attend classes at a university.
He has been suspended from his job and faces possible dismissal, while Vietnam Airlines will be checked for compliance with Covid-19 prevention regulations, quarantine processes and supervision at quarantine facilities.
More than 170,000 students at dozens of schools have been told to stay at home since some of them had come into contact with the flight attendant and the teacher.
Several coffee shops, English language centers and entertainment places the Covid-19 patients visited have been closed.
The outbreak broke Vietnam's 89-day and HCMC's 120-day streak of no community transmissions.
More than 2,200 people who came into contact with the flight attendant and three other patients have been quarantined. They have all tested negative for the novel coronavirus.