In the Cook Islands hospitals are preparing isolation beds and notices are going up at the airport as New Zealand's measles outbreak threatens infants and tourism numbers.
Health Secretary Dr Josephine Herman said extra vaccine supplies have been ordered as authorities bring down the age of immunisation from 15 months to 12months.
She said with the incubation period of up to two weeks it is possible tourists from New Zealand may come to the Cook Islands not knowing they have the illness.
"We are quite concerned now. We have about 21 flights coming in from Auckland every week. And we have quite a solid tourism industry which we would like to protect. But the main concern we have is for our babies that are 12 months or younger."
Dr Herman said all arriving passengers will be given information telling them what to do if they become unwell while they are in the Cook Islands.