A new whooping cough vaccine is needed as the virus evolves into a potential superbug, researchers warn.
University of New South Wales microbiologist Dr Laurence Luu said the virus was learning to survive in hosts whether or not they had been vaccinated.
But Dr Luu said people should still be getting vaccinated to protect themselves, with a new vaccine not needed for at least another five to 10 years.
"Right now the vaccines are still very effective against the current strain," Dr Luu said.
Dr Luu and his colleagues' work was published in the medical journal Vaccine on Thursday.
He said they had previously discovered whooping cough was learning to dodge the vaccine.
"That's part of the story but not the whole story," Dr Luu said.
"In addition to whooping cough evolving against the vaccine, it was also evolving to survive in humans better."
He said even people vaccinated for whooping cough could still be carrying a version of the disease but it would not be impacting them.
"What we're seeing is whooping cough is re-emerging all around Australia, it's not just the parts that have not been vaccinating," Dr Luu said.
"Right now the vaccines are still very effective against the current strains.
"In the future we do need a new vaccine to combat these strains as they continue to evolve."
This was important for children and pregnant women in the third trimester, Dr Luu said.
He said the last big outbreak of whooping cough in Australia was between 2008 and 2012, with more than 140,000 cases.
Deaths from whooping cough are uncommon, with the Australian Institute of Health and Welfare putting them at about two per year in the two decades leading up to 2018.
The whooping cough vaccine has been updated once before, with medicos switching to the current one in 2000 after using the previous since the 1950s.
The disease starts with a cough and cold-like symptoms, later worsening with coughs producing the distinctive "whooping" sounds. It is particularly dangerous to younger children.
Australian Associated Press