A three day mass vaccination event hasn't gone to plan. Less than a quarter of those who were invited actually signed up.

Health officials had to expand the invite list twice to find 12,000 more people to make sure the event could go ahead.

A total of 140,000 invites were sent out before they got the numbers they needed.

Heather du Plessis-Allan asked immunisation advisory centre's medical advisor, Peter McIntyre why so many of those invited didn’t want to sign up for the jab.

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