On Wednesday two patients at nursing hospitals died after receiving the AstraZeneca vaccine.
The first patient a man in his 50s got the shot on Tuesday at a nursing hospital in Goyang, Gyeonggi-do Province.
11 hours later, he began to experience chest pains and breathing difficulties.
The symptoms briefly improved with emergency care,only to return the next morning, when he passed away.
The 63-year old man was vaccinated on Saturday in Pyeongtaek, also in Gyeonggi-do Province.
He began to develop a fever and body pain 33 hours later,which repeated on and off before he died on Wednesday.
Both recipients had underlying conditions, but it is not yet clear if their deaths are directly linked to the vaccines.
"The cases are currently under investigation. We plan to find out if there's a direct correlation with the vaccinations,… by looking into their medical records,.and a study carried out by the vaccination task force."
The authorities will also be looking into whether there were any problems with the vaccine itself or the inoculation procedure.
In the meantime, they will also investigate any examples of allergic reactions known as anaphylaxis, three suspected cases have been reported so far among the 2-hundred-9 total cases of side effects.
While these cases are likely to spark concerns over vaccinating those with preexisting conditions, the government still believes people in this first priority group should get their shots.
"Patients with chronic diseases require vaccinations since they are in the high-risk group. Clinical data shows the vaccines' safety and efficacy on those people have been pretty much same as with others."
However, the government is advising medical staff to take extra caution when inoculating people with underlying conditions,.and even to reject giving the shots when necessary.
Lee kyung-eun, Arirang News.