More than 500,000 people age 65 and older in Ireland are at risk of getting pneumococcal disease, or pneumo, this winter.
Pneumo is a bacteria which can cause serious illness including meningitis, pneumonia and septicaemia.
Of those who get infected with pneumo, one in four will develop meningitis, one in four will develop pneumonia and one in 10 will die.
Currently, 84% or more than 500,000, of over 65s are not protected against pneumo.
Those aged 65 and over are at increased risk of pneumo infection, however children under the age of five and people with weakened immune systems also have a higher risk of infection.
Those who are officially at-risk according to the Immunisation Guidelines for Ireland include people with diabetes, asthma, heart disease, as well as those with chronic renal disease and chronic lung problems.
"It is disappointing that there are more than half a million 65 year olds and over in Ireland who have not been vaccinated against pneumo, or pneumococcal disease. A pneumo infection can cause serious illness and even result in death," said Dr Andrew Murphy, Galway-based GP.
"We know the introduction of a nationwide vaccination programme for pneumo almost a decade ago, has resulted in a 90% fall in cases. It is important to maintain that success rate and continue to protect at-risk groups.
"If you are 65 or older, or in one of the official at-risk groups, speak to your GP or pharmacist about protecting yourself against pneumococcal disease this winter."
The Immunisation Guidelines for Ireland recommend that infants, official at-risk groups and everyone aged 65 years or older should be offered pneumococcal vaccination.
To find out more on how to protect yourself or the ones you love against pneumococcal disease, talk to your GP or your pharmacist.
You can also visit pneumo.ie.