A further 155 Covid cases in the community have been reported in Samoa, taking the total number to 622 in less than a week after the country's first community case was discovered. 

While 90 per cent of the eligible Samoan population are vaccinated, the country's booster and child vaccinations campaigns have not yet started. 

Auckland University epidemiologist Rod Jackson says for Samoa to get ahead of the Covid curve, it must immediately start boosting its elderly. 

The majority of the Covid community infections are in the age group between 15-35 years old. 

Jackson said along with the practical public health messages of mask-wearing, keeping distances and limiting gatherings, booster shots for the elderly must be the number one priority. 

"The good news is Samoa has a high vaccination rate," Jackson said. 

"But If they are doubling in a short space of time, they are looking at a major outbreak and they must slow down the spread. That is what will overwhelm the health service. 

"That is what has made omicron more lethal than previous forms of Covid, even though it is less severe. 

"If the outbreak is happening right now, their high priority has to be to boost the oldest and work their way down." 

Samoa is also deploying thousands of rapid antigen tests - more than 11,000 since Monday, March 21 - as it tries to deal with this outbreak. 

On Tuesday, Samoan Prime Minister Samoan Prime Minister Fiame Naomi Matafaa locked down the country for a further 14 days. 

Mataafa said home isolation was not a reality in Samoa. 

"Home isolation is very hard to implement in Samoa given our communal living arrangements," she said. 

"Majority of our people don't live in fale palagis (European homes) with separate rooms. Perhaps look into setting up some of the fale komikis or church halls in the villages as quarantine sites for our villagers who are positive and asymptomatic." 

She urged all unvaccinated Samoans to get vaccinated. 

New Zealand Foreign Affairs Minister Nanaia Mahuta said Aotearoa will support Samoa in every way possible. 

"Aotearoa New Zealand is concerned about the recent emergence of Covid-19 in Samoa. We stand in solidarity with the government of Samoa as it responds to this challenge," she said. 

"We are in close contact with the government and are responding to requests for assistance as they arise."