Authorities in South Korea said the COVID-19 vaccine made by AstraZeneca and Oxford University had a 100-percent efficacy rate two weeks after the shots among people aged 75 or older, while Pfizer vaccines had a 93-point-two-percent prevention rate.

In an address to the nation on Monday, acting Prime Minister Hong Nam-ki stressed that the safety and efficacy of the two vaccines currently being administered in the country have been approved around the world.

Out of 751-thousand-687 seniors who had the first of two shots between February 26 and April 21, 28 later tested positive for the virus. That is about three-point-seven for every 100-thousand.

After the two-week period likely required for the formation of antibodies, only two people who had the first of two Pfizer shots were confirmed with the virus.

This compares to 906 out of three-point-14 million people from the age group who have yet to get the shots contracting the virus during the same period, which is about 28-point-nine out of every 100-thousand.