The Pacific island has declared a state of emergency and closed schools as it tries to contain the outbreak.
The death toll from a measles epidemic in Samoa has risen to 20 as the outbreak rages out of control, with hundreds of new cases emerging daily, official data released on Friday showed.
The government said on Friday that there were 1,644 cases, 202 of which were diagnosed since Thursday, mostly affecting young children.
It said the number of deaths had hit 20, including 19 children under four years old.
An additional 11 children are critically ill in hospital.
Samoa has declared a state of emergency as it tries to contain the outbreak, launching a compulsory vaccination programme, closing schools and banning children from public gatherings.
Australia and New Zealand have sent medical specialists and supplies, while the United Nations children’s agency UNICEF is distributing more than 110,000 doses of measles vaccine to Samoa’s population of about 200,000.
Tonga and Fiji have also experienced outbreaks, although much less severe and without any deaths so far due to higher vaccination rates among the population.
Children are the most vulnerable to measles, which typically causes a rash and fever but can also lead to blindness, brain damage and death.
Samoa has closed all schools, kindergartens and the country’s only university in a bid to halt the virus’ spread.
UNICEF estimates Samoa’s vaccination rate is 28-40 percent, while in Tonga and Fiji they are 99 percent and 81 percent respectively.
The country’s vaccination programme was briefly suspended last year when two babies died shortly after being given the MMR vaccine.
Subsequent investigations found the problem was not the widely used vaccine but the fact that the nurses administering prepared it incorrectly.
The outbreaks in the Pacific are part of a global surge in measles, with the World Health Organization (WHO) recording three times as many cases in 2019 than 2018.
The WHO says that while misinformation has made parents hesitant to vaccinate their children, poor health services in some countries have also contributed, as well as access to these services being disrupted by conflict or natural disasters.