The Ministry of Health said in the past 24 hours, there were another 198 cases of measles recorded, bringing the total to more than 3700.
Of the 48 deaths, 44 where among children younger than 4.
The Samoa Observer reports all government branches, save for water and power utilities, will close as of Thursday, with workers deployed on vaccination efforts.
A state of emergency was declared in mid-November, with schools closed and children banned from public gatherings, such as church services, to minimise the risk of contagion. Since Saturday, 173 new cases of measles have been registered and four people have died. "When measles begins a country like that, there is a huge group of people who are not safe", she said. Some 180 people remain in hospital, including 19 children who are in a critical condition.
While New Zealand and Australian aid is hitting the ground, the nature of the disease's spread makes the arrival of vaccinations something of a damage control exercise.
Neighboring New Zealand and a number of other countries and organizations, including the USA agency UNICEF, have provided thousands of vaccines and medical supplies and dispatched medical personnel to help with the outbreak.
The United Kingdom has also sent a team of medical professionals and Australia has provided medical staff, equipment and supplies. "They'll be doing that in Samoa and it means sometimes things can be worse before they are better".
That low rate was exacerbated by a medical mishap that killed two babies who were administered a vaccine that had been incorrectly mixed, causing wider delays and distrust in the vaccination program.
Officials say the anti-vaccination message has resonated in Samoa because of a case a year ago when two babies died after receiving measles immunisation shots.
The World Health Organisation has set a target of wiping out measles from most of the world by next year.