Only five localities, namely Bac Ninh, Ha Tinh, Cao Bang, Phu Yen and Bac Giang, have kick-started the second phase, while many other have yet to endorses it, the NIHE reported.
The immunization campaign in some localities has yet to meet expectations. Besides, the duration of vaccine use is quite short, up to 2 months, to monitor, said the NIHE.
The institute proposed the administrations of cities and provinces soon approve the plan to deploy the campaign, the second phase, so as to achieve the progress of the programme.
The Ministry of Health earlier warned localities to complete the vaccination plan before May 5, and it would recall the delivered vaccine if any locality does not use it up.
To date, more than 80,800 people have been vaccinated against COVID-19 since the campaign was launched on March 3, according to the MoH.
Vietnam is currently using the coronavirus vaccine supplied by the AstraZeneca manufacturer.
No serious side-effects, including blood clotting, have been reported in Vietnam, said the MoH.