Sixty-four cases of whooping cough have been logged in Buller since November, but the rest of the West Coast has largely escaped.
Twelve cases were reported in just one week earlier this month, and five more in the past week.
West Coast medical officer of health Dr Cheryl Brunton said some of those people had been admitted to hospital and all had recovered.
She said they were not trying to stop the epidemic, but to protect babies aged under a year.
