A Whangārei school which feared more than half of its pupils had never been immunised against measles has found most of them are.
Hora Hora Primary asked families for vaccination certificates this month, to find out how many of its 400 pupils were at risk from the current measles outbreak.
But the parents of 250 children had no records.
Principal Pat Newman said with the DHB asking schools to look at excluding unprotected children for two weeks, that could have meant banning or quarantining half the school.
But after two weeks of painstaking data-matching, Northland DHB staff had been able to confirm that only about 50 Hora Hora children were unvaccinated, he said.
"After data-matching our records with the DHB's records we find it's down to about twelve families where the parents don't want them vaccinated and another 40 that hadn't thought about doing it."
He said that meant about 88 percent of children at the school were protected. It was not the most effective immunity level, however it was not bad.
The school was now talking to those parents about getting their children vaccinated.
"We've already had one lot of families coming to us and asking if we could arrange to have it happen at school, and we are...looking into that," he said.
He said it would be helpful if DHBs and schools could share data about which children were vaccinated.
"The difficulty we've got at the moment is that their records and our records don't talk. So, a lot of manual entry has to be done and I'm hoping to talk to the DHB about how we can make it more automatic so every school in Northland can data-match."
In its latest update Northland DHB said two cases of measles had been reported in Northland so far this autumn.
The region has the lowest immunisation rates in the country.