Seniors are forgoing the pneumococcal pneumonia vaccine because they feel "younger and fitter" than their parents at the same age.
The vaccine has been proven to increase average lifespans by more than a year but Lung Foundation Australia research found 87 percent of seniors aged 65 to 74 said they were in better health than their parents' generation, and did not need a vaccination.
The study also found 65 percent of seniors did not consider their age to be a health-risk factor.
Lung Foundation Australia national council member Lucy Morgan said she applauded their positive attitude but the statistics didn't lie -- 52 per cent of this age group were at increased risk of contracting pneumococcal pneumonia.
"We are seeing the rise of a generation of healthy, fit and fabulous Australians in their mid-60s who love to travel and to care for their grandchildren," said Morgan, who is also a respiratory physician at Concord Hospital.
"They take good care of themselves, and are dedicated to adding years to life, by exercising and eating well, but don't realise that developing pneumococcal pneumonia could change all of that.
"The stark reality is, all adults aged 65 and over are at increased risk of contracting pneumococcal pneumonia due to their age alone."
What is pneumococcal pneumonia?
Pneumonia is an inflammatory lung infection caused by either bacteria, a virus or fungus, often developing after a cold or flu.
It can cause the lungs' air sacs to fill with fluid causing difficulty breathing, coughing and in some cases, hospitalisation and death.
Pneumococcal pneumonia is caused by one particularly nasty bacteria called streptococcus pneumoniae.
The study released as part of Pneumonia Awareness Week, on until May 15, also found 40 percent of 65–74 year olds didn't know a pneumococcal vaccine existed.
"Furthermore, only 17 per cent of Australians aged 65–74 are even aware that pneumonia is among the top five leading causes of hospitalisation in Australia," Morgan said.
In Australia, the pneumococcal vaccination is funded under the government's National Immunisation Program for Australians over the age of 65.
Lung Foundation Australia chief executive Heather Allan said pneumonia particularly affected infants;, people aged over 65, smokers and people with chronic illness.
"Pneumonia-like illness (flu and pneumonia) is one of the top 15 contributing causes of death in Australia -- the illness can affect anyone," Allan said.
"While Australians are aware of the importance of eating well and exercising regularly, they are relatively complacent when it comes to protecting against pneumococcal infection, including good personal hygiene and vaccination."