Russia's Interfax news agency reported on Friday the Sputnik V vaccine had been approved, though Vietnam's health ministry said that a medical panel had recommended it and the U.S. Moderna Inc vaccine for use.
Approval by the health ministry is needed for the purchase and use of vaccines in the country.
Vietnam approved the AstraZeneca vaccine late last month.
Foreign Ministry spokeswoman Le Thi Thu Hang said that the health ministry and businesses were in talks to buy more vaccines, including Sputnik V and the Pfizer-BioNTech vaccine.
"Vietnam wishes to have access to sources of quality COVID-19 vaccines at reasonable prices and suitable for Vietnam's storage conditions," Hang told a news conference on Thursday.
The government ruling said frontline workers, security forces, diplomats, teachers and people of 65 or older will be among the first to be inoculated, for free.
Vietnam was lauded globally for its record in containing the virus for long spells last year through mass testing and tracing and strict quarantining, though it has faced a recent wave of infections.
The country has recorded 831 new COVID-19 cases since the latest outbreak started last month, or about a third of its overall caseload of 2,426 infections.
It has reported just 35 deaths due to the virus.