A new study reports that Ebola damages young children quicker than adults. Researchers said Wednesday that roughly 90 percent of babies under the age of one who become infected die.

The Ebola virus caused a devastating number of deaths in West Africa, and children experienced the symptoms sooner. They also required hospitalization sooner and died days earlier than adults, according to the World Health Organization’s Ebola Response Team.

Although the infection rates are lower for children, they have a much lesser chance of survival. Co-author Christopher Dye said that whoever develops the virus needs “the best care promptly.” He added that with children, “we need to be vigilant.”

And Christl Donnelly, a researcher who co-lead the Imperial’s Centre for Outbreak Analysis and Modelling, said that it is important that children get the treatment “appropriate for their age.” The scientists discovered that the virus, which causes vomiting, internal and external bleeding and haemorrhagic fever, is killing 80 percent of children between the ages of one and four in the current outbreak and 90 percent of infants.

Older children have a much higher chance of survival. Reuters reported that 52 percent of children infected between the ages of 10 and 15 survived the disease. A co-researcher on the study, Robert Fowler, stated that the very youngest children, or neonates, have the “worst outcomes from Ebola.”

The findings from the study, published in the New England Journal of Medicine, also revealed that symptoms differed between children and adults. Children are more likely to have a fever than adults, but they are less likely to have trouble swallowing or breathing. They are also less like to have abdominal, chest, joint or muscle pain.

Until now, little about the effects of Ebola on children has been known because children are less likely to contract the virus, according to Dye. For instance, less than 4,000 cases were reported in children under the age of 14 and more than 11,000 were reported in people ages 15 to 44. Additionally, children do not care for those with the disease, and that is one of the most frequent ways people contract the virus.