Senior citizens who had made reservations for the AstraZeneca vaccine but had yet to be inoculated this month will instead receive the Pfizer vaccine next month. 

According to the state task force on vaccination on Monday, around 200-thousand people - including those aged 60 to 74 and those suffering from chronic respiratory diseases - will receive their first shots of the Pfizer vaccine from July 5 to July 17. 

Appointments will begin on Wednesday and remain open through next Wednesday. 

The change of plans is known to be due to the vaccine supply schedule for the third quarter. 

Earlier in the day, Sohn Young-rae, a senior Health Ministry official, said the July to September period will see administration of the Pfizer and Moderna vaccines.