So-called booster shots of the COVID-19 vaccine will begin from October.

In a Monday briefing, Jeong Eun-kyeong, head of the Korea Disease Control and Prevention Agency(KDCA), said that a timetable is being set up for boosters from the fourth quarter for people who have been fully vaccinated for at least six months.

The shots are meant to boost the vaccine's preventive effects. For those who received a two-dose regimen, the booster would be their third shot.

Jeong explained the decision to add a booster regimen after observing that antibodies were found to decrease and incidents of breakthrough infections rose after a period of time. She also noted the spread of the highly transmissible delta variant.

She relayed an expert committee's opinion that people with weak immune systems should receive boosters even before the recommended six months.