People who might have been exposed on those flights should be vigilant for symptoms of the highly infectious disease, said the service's Medical Officer of Health, Maria Poynter.
The passengers were on an Air New Zealand flight NZ959 leaving Apia at 9.40pm on Friday 8 November, and the same flight at the same time on Sunday night.
Dr Poynter said it could take seven to 14 days to start experiencing symptoms and non-vaccinated people were most at risk.
