Waikato District Health Board is using social media to encourage teenagers to challenge their parents' decisions about immunisation following an outbreak of measles in the region.
It says there have been 19 confirmed cases in the region, all affecting people aged between 13 to 20.
In all the cases they have either not been immunised or have failed to finish their course of MMR vaccines.
The Health Board says it is using social media such as Facebook and Twitter to reach teenagers.
It is urging them to ask their parents about whether they are immunised and how their parents came to that decision.