Group 3 includes people aged 65 and over, people with some underlying health conditions, pregnant people, people with disabilities, older Māori and Pacific people, the people they live with and their carers.
"There are more than 170,000 people in Group 3 in Canterbury. Because of this, we're inviting people to book their vaccination appointments in stages."
People in Group 4 will be starting to receive notifications about being able to make a booking, from tomorrow. The first age band is people aged 60 years and over.
In a post on Facebook, the CDHB said it nearly doubled its vaccination capacity last week, going from 10,000 to almost 20,000 doses administered.