World health authorities are now helping Samoan officials investigating the deaths of two children who died shortly after receiving an MMR vaccination.
The World Health Organisation and the United Nations International Children's Emergency Fund (Unicef) have issued a statement indicating their involvement in the tragic case.
"Unicef and the WHO are deeply concerned about the deaths of two children in Samoa last week after they received a routine measles, mumps and rubella (MMR) vaccine.
"The deaths of these two children is a tragedy and our thoughts and prayers are with their families and the people of Samoa.''
A spokesman for the organisation said representatives were working closely with the Samoan Government; whose Prime Minister this week called for a full inquiry into the circumstances of the deaths of the two 1-year-olds who died after receiving a vaccination at Safotu District Hospital, on the island of Savaii, last Friday. The autopsies of youngsters Lannacallystah Samuelu and Lameko Si'u - the latter celebrating his first birthday a few days ago - are due to take place this week.