Under the direction of the Government, the Ministry of Health and localities, most of the population have been fully vaccinated against COVID-19 by February. However, antibody levels among vaccinated people decline after 4-6 months.
The booster shots are essential for those with compromised immune systems and old people to get a longer immunity, Lan said, adding that they should be injected on schedule and at the right dose.
He also stressed the importance of vaccinating frontline health workers because they belong to high-risk groups, saying it will help reduce the infection to other people.
Referring to concerns about the possibility of children infected with BA.4, BA.5, subvariants of Omicron, Associate Prof. Dr. Tran Minh Dien, Director of the National Paediatric Hospital, said that studies have shown that between 20%-25% of children infected with COVID-19. Most severe diseases are mainly related to chronic or underlying diseases.
If the subvariants BA.4, BA.5 spreads rapidly in the community, there might a transmission from children to old people and adults due to the fact that they are not good at following instructions on COVID-19 prevention as adults.