South Korea's daily COVID-19 cases were slightly lower on Sunday compared to recent days due to fewer tests being conducted on the weekend.
The country reported 556 new infections below the 600 mark for the first time since June 1st.
Of the new cases, 541 were local transmissions, and 15 were from overseas.
The health authorities remain alert over the spread of more transmissible variants, and sporadic infections that continue to pop up nationwide, at workplaces, restaurants, bars and other places.
"The daily average COVID-19 tally in the past six weeks has stagnated in the high 500s. The reproduction rate is at zero.9-7, the same as the previous week. But we can't let down our guard. Please keep in mind that there are still infections occurring as we go about our daily lives, and please adhere to the quarantine rules."
As of Sunday, almost 7.6 million people in Korea have received their first dose of a coronavirus vaccine, which is about 14.8 percent of the population.
And nearly 2.3 million around 4.4 percent of the population have been fully vaccinated.
Starting Monday, the country will begin giving first shots of AstraZeneca vaccines to people aged 60 to 64.
Authorities are again calling on seniors who've not yet gotten their shots to do so.
"The goal of our vaccination campaign in the first half is protection for the elderly. Until June 19th, people aged 60 and older get priority when claiming leftover vaccines. South Korea's top priority is to provide protection for senior citizens, as those 60 and older are at higher risk from COVID-19."
Also on Monday, first jabs of the Pfizer vaccine will begin for some 414-thousand military troops under the age 30.
Meanwhile, first and second grade teachers at elementary schools, and workers at kindergartens and daycare centers, can reserve the Pfizer vaccine starting Monday if they're under the age of 30.
Those eligible can make bookings until the start of vaccinations in mid-June.
Kim Jae-hee, Arirang News.