Samoa finalized plans for a compulsory measles vaccination program on Monday, after declaring a state of emergency as a deadly epidemic sweeps the Pacific nation.

Aerial photo taken on Oct. 20, 2019 shows Taumeasina Hotel in Samoa. (Xinhua/Guo Lei)

At least six fatalities, including five children, have been linked to the outbreak of the virus, which has also hit other island states such as Tonga and Fiji.

Samoa is the worst affected with more than 700 cases reported from across all areas of the country, prompting the government on Friday to invoke emergency powers.

Declaring a state of emergency, the government said plans for compulsory measles, mumps and rubella (MMR) immunizations would be published on Monday.

"MMR vaccinations for members of the public who have not yet received a vaccination injection is now a mandatory legal requirement for all of Samoa," it said.

A national emergency operations centre to coordinate the measles response in the nation of 200,000 people was opened on Monday, with children aged six months to 19 years and non-pregnant females aged 20-35 given priority.

However, no information was immediately available on how the vaccinations would be administered or whether those who were not immunized would face sanctions.

Children are the most vulnerable to measles, which typically causes a rash and fever but can also lead to brain damage and death.

Samoa has closed all schools, kindergartens and the country's only university in a bid to halt the spread of the virus.

Fiji has reported four cases but says they are contained to a township west of the capital Suva.