The Cook Islands has suspended all MMR vaccinations, covering measles, mumps and rubella.
The decision was made following the deaths of two infants in Samoa after they were immunised with the same batch of MMR vaccine.
The move is precautionary said the Cooks Islands' Secretary for Health, Josephine Aumea Herman, as they get their MMR vaccine from the same supplier as Samoa, via the United Nations Children's Fund.
Dr Aumea Herman said the suspension is temporary and the health ministry is awiting the results of an investigation in Samoa into the deaths of the two infants there.
"Vaccinations have been life-saving for many children across the globe and for an incident like this it's important that we wait for the information to be collated and that's the investigation that's being undertaken," said Dr Aumea Herman.
"I'm not too clear in terms of when this might happen but for the time being the Cook Islands has temporarily suspended."
Dr Aumea Herman said the country has a 100 percent MMR infant vaccination rate and that this suspension will temporarily affect only around ten Cook Islands' babies.