The Samoa Red Cross says people in the Pacific nation are panicking, with 32 people confirmed dead from measles.
There are almost 2,500 people infected, with 176 of them in hospital.
There has been a spike in cases since the mass vaccination programme began last week, with nurses saying many will have had the disease and been contagious before the first symptoms were showing.
In the last six days, 24,000 people across the two main islands of Upolu and Savaii have been vaccinated.
The Samoa Red Cross has been assisting the Health Ministry in its programme, and New Zealand Red Cross nurses are also on the ground.
The Secretary-General of the Samoa Red Cross, Namulauulu Tautala Mauala told Alex Perrottet people are afraid to go to the hospital and mobile clinics are proving useful in getting vaccines to as many people as possible.