Parents are being reminded to watch out for the signs of bacterial meningitis.
It is after a survey of 375 Irish parents by GSK found that just over a third are still unaware of symptoms of the disease, which mainly affects babies and young infants.
The survey shows that vomiting, seizures and cold hands and feet are the least known symptoms..
GSK are launching a campaign to raise awareness of the disease, as part of World Meningitis Day.
Vaccines Medical Director Dr Philip Cruz says babies and young infants are most at risk, and if symptoms aren't caught quickly the consequences can be fatal.
He said: "It can be very devastating the terms of how the symptoms can progress, from being just symptoms like the flu whereby progressing to a more sick patient and can be really devastating leading to death in a matter of 24 hours."
Dr Cruz said things like a rash, stiff neck or a dislike of bright light are signs, but there are also others.
He said: "The signs and symptoms can actually resemble flu.
"For babies its worthwhile to note that they can be a decrease in appetite in feeding, they can be drowsy most of the time, and when you carry the baby there's this floppy muscle tone, especially in infants of one year of age."