The head of the Ministry of Health in Samoa has ordered the immediate recall of all measles, mumps and rubella (MMR) vaccines after the deaths of two one-year-olds.

The children were given the MMR vaccine on Friday at Safotu Hospital on the island of Savai'i. However within minutes they were dead. One child was allegedly immunised without the mother's consent - and despite her protesting.

Health Ministry CEO Dr Take Naseri says a full investigation is underway into the deaths. All MMR vaccines in Samoa have been ordered to be seized and the staff involved have been stood down, TV1 Samoa reports.

Prime Minister Tuilaepa Lupesoliai Dr Sailele Malielegaoi says he is waiting to be fully briefed on the situation.

"I have called a full inquiry into the circumstances leading up to this devastating incident which I do not take lightly," he told media.

"There are already processes that will determine if negligence is a factor. And if so, rest assured those processes will be implemented to the letter to ensure that such tragic [deaths] will not be repeated and those responsible will be made to answer."

Newshub.