Massive differences in vaccination rates at GP practices just a few kilometres apart has prompted calls for a funding overhaul.

A Grattan Institute report has found 10-fold or even 18-fold differences in vaccination rates, especially pneumococcal, between GP practices in suburbs like Sydney’s Bankstown or Melbourne’s Wyndham.

The institute’s health program director, Peter Breadon, said the level of variation was a surprise, although the patient factors linked to lower vaccination rates were not.

These included older age, economic disadvantage, not speaking English at home and not seeing a GP regularly.