The Immunisation Foundation of Australia released data on Monday showing more than 4500 cases of severe pneumococcal had been recorded in the past 24 months, the largest number of recorded infections since 2002.
Pneumococcal bacteria can cause a range of diseases including meningitis and pneumonia, with small children and the elderly most at risk.
An infection is treated with antibiotics.
Pneumococcal vaccinations help prevent antibiotic resistant infections. (James Ross/AAP PHOTOS)
The infection can prove deadly within days, with pneumococcal meningitis claiming the lives of one-in-12 children with the disease.
The immunisation foundation is urging the federal government to prioritise broader-coverage pneumococcal vaccines that have been approved by the Therapeutic Goods Administration.
Pediatrician and infectious disease researcher Peter Richmond said there were hundreds of non-invasive infections such as bronchitis, sinusitis and middle ear infections that left children and the elderly suffering.
"We're seeing a drop in vaccine coverage alongside emerging strains of the bacterium and antibiotic resistance," Professor Richmond said.
"It's important to recognise that effective pneumococcal vaccination helps prevent antibiotic resistant infections."
Factors believed to be driving the increase in invasive pneumococcal disease include evolving strains, declining vaccination rates and antibiotic resistance.
Fully vaccinated coverage rates for children in Australia are declining. (David Mariuz/AAP PHOTOS)
Childhood vaccination rates fell from 93.3 per cent in 2022 to 92.8 per cent in 2023 in one year olds.
Founder and director of Immunisation Foundation of Australia Catherine Hughes said newer pneumococcal immunisations protected against more strains than available vaccines.
"Invasive pneumococcal disease can cause permanent disability and even death," Ms Hughes said.
"We have the tools to make a difference, and now is the time to ensure Australians at greatest risk of infection are protected."