South Korea on Thursday began inoculations using Janssen's COVID-19 vaccine supplied by the U.S.
Of the slightly more than one million doses received, roughly 894-thousand will be given to those working in national defense or foreign affairs in the age range of 30 to 60.
Health authorities first opened reservation spots for 900-thousand doses all of which were fully booked in just 18 hours.
The other 110-thousand doses are reserved for people who have to leave the country quickly for government or business affairs, or are living on hard-to-reach islands where there are no doctors.
Doses for those living on the islands will be distributed by navy vessels starting mid-June.
Clinical trials show that the one-shot Janssen vaccine is over 66 percent effective two weeks after the shot.
As of Thursday, a total of more than nine.seven million people have received their first dose of a COVID-19 vaccine, that's 19.one percent of the country's population.
South Korea recorded 611 cases on Thursday.
Of those, 594 were local and the rest came from overseas.
More than 60 percent of the daily caseload came from the capital region.
154 people are severely ill and with two additional fatalities, the total death toll stands at over 19-hundred.
Jang Tae-hyun, Arirang News.