SEOUL, South Korea has reported nearly 4,000 coronavirus infections involving people who tested positive for COVID-19 after being fully vaccinated, health authorities said Tuesday.

Out of more than 9.75 million people who have received the full-dose vaccine regimen, there were 3,855 breakthrough cases, the Korea Disease Control and Prevention Agency (KDCA) said.

The rate of breakthrough cases occurring in people in their 30s was the highest at 0.092 percent, with the rate decreasing among the elderly, the KDCA said.

The rate of breakthrough cases among those who have received jabs supplied by U.S. pharmaceutical giant Johnson & Johnson came to 0.131 percent, trailed by AstraZeneca with 0.042 percent and Pfizer with 0.023 percent.

The KDCA said similar cases may increase as the country's vaccine rollout revs up, though the proportion of breakthrough cases is extremely low.

Since its nationwide inoculation campaign began in late February, more than 60 percent of the country's 52 million population, have received their first shots of COVID-19 vaccines, the KDCA said.

The rate of breakthrough cases occurring is 0.04 percent, and the benefits of vaccination outweigh the risk of becoming a breakthrough case, the authorities said.

Source: Yonhap News Agency