Two days into online vaccine bookings for those aged 18-49, South Korea has experienced no major errors and system crashes so far, unlike previous sessions for other age groups.

According to government officials, the main reason behind the smoother operation is a reduction of traffic. The country has divided the eligible population into 10 groups, depending on the last digit of their birth date, and allows them to book their vaccine slots only on a designated day that matches their number.

With booking on behalf of other people not allowed, this has reduced the maximum number of people approaching the system per day to around 1.7 million.

IT specialists were also mobilized to solve system overload problems, including those from LG CNS, the unit of LG Group said.

According to the firm, in previous booking sessions, massive simultaneous access to shared resources caused bottlenecks on the server, as many people flocked to the system as soon as it opened.

LG CNS said its team worked over five days at the request of the Korea Disease Control and Prevention Agency, made on July 23, and has improved the server’s performance by around 90 percent. The company added that its team optimized and increased the server capacity to handle higher server load.

The server can now handle 2 million people per hour, up from 0.3 million, according to LG CNS.

A total of 17 million people aged 18 to 49 will make reservations on the system by next Thursday.