South Korea added 355 new Covid-19 cases on Monday marking the second straight day that the daily caseload stayed below 400.
But, that's due in large part to fewer tests being taken over the holiday weekend.
Of those cases, 17 were from overseas and two more deaths were confirmed raising the death toll to 1,6-hundred-and-five.
Health authorities have also added 14 more cases of the more transmissible Covid-19 variants taking the total to 156.
Meanwhile, having given shots to 765 people nationwide on Sunday, the country had vaccinated 21,1-hundred and 77 people three days after it launched its mass immunization against Covid-19.
The KDCA said Monday that 152 people have reported mild reactions or side effects to their coronavirus shots.
"All of the cases reported as side effects were common symptoms that typically occur when a immune system reacts to a vaccine. They did not last long and mostly disappeared within about three days."
The most common side effects after getting the vaccines were fever, muscle aches and headaches followed by nausea, chills and skin rash.
The KDCA chief added vaccinated people must still wear masks, follow strictly the social distancing guidelines and safety protocols as she pointed out the importance of maintaining community-wide adherence to guidelines while much of the population is still at risk.
South Korea aims to have 70 percent of its population inoculated with their first vaccine shots by September and achieve "herd immunity" by November.
The nation's health authorities plan to monitor 200 recipients of each vaccine it's administering - the AstraZeneca's and Pfizer's - to determine when they have formed antibodies and how long immunity lasts once someone receives the shot.
South Korea has also reached agreements with Moderna, Novavax and Johnson and Johnson for vaccine procurements.
Bae Eun-ji, Arirang News.