Health Minister Tony Ryall has told the West Coast District Health Board to "talk harder" to the Gloriavale Christian Community to try to convince leaders to vaccinate their youngsters.
Members of the religious sect, who now number over 400, living communally on the shores of Lake Haupiri, wore face masks during the recent whooping cough epidemic on the West Coast. They promote breast-feeding as a way of boosting their children's immune system, but reject vaccinations.
But as Gloriavale grows it numbered 378 at the 2006 census the overall vaccination rate on the West Coast falls, dropping to 79 per cent in the last quarter.
DHB chairman Dr Peter Ballanytne told members at their meeting in Greymouth on Friday that the minister wanted the board to try harder to bring Gloriavale into the vaccination programme.
"He doesn't accept that groups just say 'no'."
Board member Mary Molloy said talking more might pick up one or two others in the wider community.
Meanwhile, the board was also told it was still under scrutiny with its forecast of a large deficit.
"We are under intensive monitoring and close watch," chief executive David Meates said.