Dinh Tien Dung, municipal Party Committee Secretary, said the city of 10 million would require 5-6 million doses to reach herd immunity.

"Demand for the vaccine is high and the need is ever more urgent. But the capital's current budget for Covid-19 prevention is still too small," said Dung while calling on benefactors for help.

Hanoi aims for 95 percent of its most vulnerable population segment against Covid-19 to be vaccinated. The capital would use its own budget to purchase, transport and store Covid-19 vaccines, besides the doses that have already been distributed by the Ministry of Health.

The capital has recorded 352 local Covid-19 cases in the nation's latest coronavirus wave, including 139 in its locked down National Hospital for Tropical Diseases and K Hospital.

Vietnam began a mass Covid-19 vaccination program in March that has seen over a million people, mainly frontline workers of the Covid-19 fight, inoculated.

The country aims to secure 150 million vaccine doses by next year to cover 70 percent of its population.