Westland Medical Centre GP Anna Dyzel said doctors had seen "a significant number" of children with the virus.
"The disease spreads quickly, as people are contagious for five days before the spots appear - so before they realise they're unwell," Dr Dyzel said.
The infectious period continued until five days after the last spot had appeared.
"So the infectious period can be as long as 15 days," Dr Dyzel said.
"The disease was added to the vaccination schedule in 2017, but there are a number of children who haven't been vaccinated as yet and `herd immunity' won't be at a decent level for a decade."
The vaccine was funded only at 15 months and 11 years.
"This means that control relies on people keeping their children home for the full infectious time."
- Janna Sherman
