American Samoans have been praised for their high vaccination rates and told this is preventing a measles outbreak.
Last month, two children with measles, visiting from neighbouring Samoa, came into contact with local residents.
The Director of Health, Motusa Tuileama Nua, said if the people the children met had not been vaccinated, the territory would definitely have had an outbreak by now.
The two children were admitted to the Intensive Care Unit, where they were isolated and nursed back to health before being discharged.
Department of Health epidemiologist Aifili John Tufa said as soon as anyone presented with symptoms, they conducted contact tracing, and in this case established that all those the children had met had been vaccinated.
The department puts the country's MMR vaccination rate at 99.7 percent.
But Dr Tufa said there was still work to be done to up the rate for the 1-5 year age group, which is currently at 84.7 percent.