Half of the vaccination appointments made available for people aged 46 to 49 were booked in the first 30 minutes, the health ministry said on Friday.

Some 5,770 people arranged appointments by 8am. The vaccination portal opened with 11,220 appointments for the age group at 7.30am. It will remain open until 5.30pm on Saturday.

According to the health ministry, 490,456 vaccine doses were administered as of May 20.

Some 353,168 people received the first dose (47.7 per cent) and 137,288 people have completed their vaccination (18.6 per cent).

The health ministry is expected to announce the age groups that will be prioritised next week.