Starting Monday, South Korea will begin mix-and-match inoculations for one-point-61 million people who received the AstraZeneca vaccine as their first shots. 

About 890-thousand people, including care workers aged over 30, medical workers, patients with chronic kidney diseases and essential workers, will be inoculated with Pfizer vaccines for their second jabs through the end of this month. 

These people received a first dose of AstraZeneca vaccine after mid-April and were supposed to get their second jabs on Monday, but couldn't because of supply issues. 

About 663-thousand people aged under 50 will also be eligible for the mix-and-match inoculation as the government adjusted the age limit for the AstraZeneca vaccine from 30 or older to 50 amid concerns over rare blood clots.

Those who received their first AstraZeneca shot and are now earmarked for the mix-and-match scheme will be eligible for a Pfizer vaccine as their second shot in August and September.