Pharmac says tamariki are now able to receive a newly funded vaccine against pneumococcal infections.
The disease which may cause ear and sinus infections, pneumonia or bloodstream contamination, spreads through the air by coughing and sneezing.
Previously the vaccine, called PCV13, was only funded for high-risk people.
But now it is being used as part of the childhood immunisation programme, instead of the current PCV10.
Pharmac chief medical officer Dr David Hughes said after changes on the epidemiology of the disease, the agency decided to widen access to the PCV13 vaccine.
He said Pharmac was looking into advice about catch-up doses for older children and the inclusion of Māori and Pacific children to high-risk programme.
The new vaccine will be available for those under the age of 5 who have not yet received all three scheduled pneumococcal vaccine doses, as well as those who have taken some doses of PCV10.
Access to the PCV13 vaccine will be widened from 1 December 2022.