The Food and Drug Safety Ministry announced Wednesday that it's approved the COVID-19 vaccine developed by Janssen, a subsidiary of Johnson and Johnson.
The Janssen product is a viral vector vaccine, unlike the Moderna and Pfizer ones, which use mRNA.
Also, it's given in only one dose and has an efficacy rate of 66.9 percent.
South Korea is due to receive enough doses for up to 6 million people starting in the third quarter of this year.
They'll be stored at between minus 25 degrees and minus 15 degrees Celsius, so the logistical challenges are somewhat smaller.
South Korea now has three approved vaccines to roll out, and experts say the more the better.
"We also need to get our hands on as many different types of vaccines as possible because it will give us diverse options to fight against the virus because we are now currently seeing different side effects from companies' vaccines."
South Korea has also reported a third case of blood clots, now being investigated possibly as a vaccine side effect.
The patient in her 20s got the AstraZeneca vaccine last month, and the blood clots occured 12 days later.
No causal link has yet been confirmed between blood clots and the AstraZeneca vaccine, and the European Medicines Agency is due to release its findings this week.
Dr. David Kwak, though, says the benefits of the AstraZeneca shot outweigh any risks.
"Vaccination could possibly have a causal relationship to side effects that we are currently seeing, but that does not mean that we should completely abolish and stop vaccinating AstraZeneca at this moment. Even still, the risk-to-benefit ratio considering the benefit clearly overrides the risk that we currently have at hand."
He also added that this might make the public more reluctant to go with AstraZeneca.
Another 37-thousand people got their first vaccine doses on Wednesday, so now more than one million first doses have been given, covering slightly less than 2 percent of the entire population.
The vast majority were given AstraZeneca, and about 150-thousand were given Pfizer.
And with Pfizer, more than 33-thousand people have gotten both doses.
Choi Won-jong, Arirang News.