Starting Monday, South Korea will begin inoculating COVID-19 vaccines to essential workers such as police officers, coast guards and firefighters.

According to health authorities on Sunday, these essential workers will receive AstraZeneca vaccines at medical institutions designated by relevant cities and counties.

The government had earlier planned to vaccinate them in June, but moved up the date to April.

A total of 173-thousand essential workers are supposed to take their first shots of the AstraZeneca vaccine from Monday, but those under 30 are excluded due to concerns over rare cases of blood clots.

The nation will also start administering the vaccines to health workers at medical institutions, pharmacies and patients with chronic kidney disease on Monday.