Researchers warn that a new pertussis vaccine is needed as the virus evolves into a possible superbug.
Dr. Laurence Luu, a microbiologist at the University of New South Wales, said the virus was learning to survive in guests, whether they were vaccinated or not.
But Dr. Luu said people should still get vaccinated to protect themselves, with a new vaccine that is not needed for at least another five to 10 years.
“At this time, vaccines remain very effective against the current strain,” said Dr. Luu.
The work of Dr. Luu and his colleagues was published in the Vaccine medical journal on Thursday.
He said they had previously discovered that whooping cough was learning to dodge the vaccine.
“That is part of the story, but not the whole story,” said Dr. Luu.
“In addition to whooping cough that evolved against the vaccine, it also evolved to better survive in humans.”
He said that even people vaccinated against whooping cough might still be carrying a version of the disease, but it would not affect them.
“What we are seeing is that whooping cough is resurfacing throughout Australia, it is not just the parts that have not been vaccinated,” said Dr. Luu.
“At this time, vaccines are still very effective against current strains.
“In the future, we need a new vaccine to fight these strains as they continue to evolve.”
This was important for children and pregnant women in the third trimester, said Dr. Luu.
He said the last major outbreak of pertussis in Australia was between 2008 and 2012, with more than 140,000 cases.
Pertussis deaths are rare, as the Australian Institute of Health and Welfare estimates them at approximately two per year in the two decades before 2018.
The pertussis vaccine was updated once before, and doctors changed to the current one in 2000 after using the previous one since the 1950s.
The disease begins with a cough and cold-like symptoms, and then worsens with a cough that produces the distinctive “pertussis” sounds. It is particularly dangerous for younger children.
Australian Associated Press