World Health Organization warned in October of a devastating comeback in measles epidemics as the number of reported cases rose by 300 percent in the first three months of this year.
At least 63 people, mostly children, have died since the outbreak began in mid-October, with the crisis blamed on so-called "anti-vaxxers" convincing parents that immunisations were risky.
Jessica Washington of Al Jazeera, reporting from Samoa's capital, Apia, said Friday that so far, an estimated 16,000 people have been vaccinated during the first day of mass vaccination on Thursday.
"I've seen mass mobilisation campaigns before, but not over an entire country like this", Yett said.
"The anti-vaxxers sadly have been slowing us down", he advised TVNZ.
"We have had children who died after arriving at the hospital as a last resort, and then we discovered that the anti-vaccine message has reached their families and that is why they have kept these children at home", he said.
He warned anti-vaxxers: "Don't get in the way, don't contribute to the deaths".
"We will advise the police to act when we have no other option", Attorney General Lemalu Hermann Retzlaff said in a statement.
The government backed his harsh rhetoric by arresting vocal activist against vaccination Edwin Tamasese on Thursday night and accusing him of incitement.
Samoa declared a state of emergency, and made vaccinations compulsory.
U.S. anti-vaxxers are reportedly swamping Samoan government websites with material described as "nonsense".
On Friday, Samoan Prime Minister Tuilaepa Sailele Malielegaoi said at the launch of the Samoa Measles Appeal that "through this appeal, we shall be able to get support for our national efforts to contain the outbreak and immunize our population to create herd immunity".
The south pacific nation of Samoa has shut down all non-essential services for 2 days to carry out an unprecedented measles vaccination campaign.
Yet the infection continued to spread, with the health ministry reporting 140 new cases over the previous 24 hours on Friday morning.
Measles is a extremely contagious sickness that causes coughing, rashes and fever.
Samoan authorities have blamed low coverage rates in Samoa in part on fears caused past year when two babies died after receiving vaccinations shots, according to local media reports.
The drastic action now under way aims to raise the rate to at least 90 percent, which should help to curb the current outbreak and stop future epidemics.
"In 2016 there were more than 500 measles cases in England, many in teenagers and young people attending summer festivals who'd missed out on their MMR vaccine in childhood".
The latest figures show that 54 of the 62 dead were aged four or less and infants account for most of the 4,217 cases recorded since the outbreak began in mid-October.
Tamasese, who has no medical training, has railed against vaccines on his Facebook page and advocates using quack remedies such as papaya leaf extract to treat measles.
Russian village becomes home to 56 polar bears
Until ice coverage becomes thick enough again, the bears will remain on land and search for food along the shore, he said. The bears are said to have come to the village of Ryrkaypiy looking for food, mostly in the form of walruses and seals.