A Hutt Valley High School pupil with a confirmed case of whooping cough remained at school while the disease was infectious.
Principal Ross Sinclair says the whooping cough was confirmed in a Year 12 girl on Thursday.
He says this is the first whooping cough case of the year at the school, though a Year 10 boy has suspected whooping cough.
Mr Sinclair says the biggest danger from whooping cough is to pregnant women, and they have several pregnant staff members.
Regional Public Health medical officer Stephen Palmer says whooping cough case numbers in Wellington are about the same this year as in other years.
He says there have been small outbreaks almost continuously throughout the year.