The death toll from the outbreak has risen to 53 today, with the deaths of five children. Most victims are infants and young children, including 23 children under one year and 25 children aged one to four. An adult and two older teenagers also died and the Samoa government said more than 1,100 people had been admitted to the hospital since the outbreak began. About 180 people remain in the hospital, including 19 critically ill children.
Samoa declared a national emergency last month and ordered all 200,000 people living on the island to be vaccinated.
The government has closed all schools and banned children from public meetings.
The outbreak threatens to cause chaos on the island before the holiday season, with 25 percent of the country's GDP coming from tourism.
Samoan officials believe the virus was first spread by a traveler from New Zealand.
After wreaking havoc in the Democratic Republic of Congo, Madagascar and Ukraine, among others, cases of measles began to emerge in the city of Auckland, New Zealand, a hub for travel to and from small Pacific islands.
Dr. Helen Petousis-Harris, a University of Auckland vaccinologist, said there were pockets in the community where immunization rates dropped, allowing the disease to settle.
She said, "It's really being a good global citizen, because we all have to do our part.
"I don't think the answer here was a shining example. Because, first of all, we were aware of the possibility or potential for this and that has been the case for a long time."
New Zealand Prime Minister Jacinda Ardern said her country was doing everything possible to help contain the epidemic, including sending more than 50 medical professionals and thousands of vaccines to Samoa.
Other countries, including Britain, also sent teams and supplies.
Ardern said the natural curve of infection rates means that "sometimes things can get worse before they get better."
The World Health Organization has set a goal of eliminating measles from most of the world by next year.
He says the disease is completely preventable thanks to a safe vaccine in use since the 1960s and that measles deaths worldwide fell 84% between 2000 and 2016 to about 90,000 annually, thanks to better immunization.
Measles cases are increasing worldwide, even in rich countries like Germany and the United States, as parents avoid immunization for philosophical or religious reasons or fear that these vaccines may cause autism.
Other nations, through poverty or poor planning, have lowered immunization levels, exposing their younger members to a disease that aggressively attacks the immune system.
The WHO warned in October of a devastating return to measles epidemics as the number of reported cases increased by 300% in the first three months of this year.
Officials said reported measles cases are the highest in all years since 2006.