A joint study by Queensland Children's Medical Research Institute (QCMRI) and the Royal Children's Hospital says that children vaccinated against whooping cough with the current vaccine, were three times more likely to develop the highly contagious respiratory infection than children who received an earlier version of the vaccine.
QCMRI Senior Research Fellow Associate Professor Stephen Lambert said the new vaccine for whooping cough had been introduced in 1999 into Australia's national immunization schedule as it was found to have far fewer side effects than the previous vaccine.
"Infants who aren't vaccinated have a much greater risk of contracting the disease and developing serious complications," Lambert said, reassuring parents that vaccination still offers the best protection against developing whooping cough.
Lambert said before 1998 the whooping cough vaccine was made up of whole cells of the dead Bordetella pertussis bacteria.
"While it was generally a highly effective vaccine it commonly caused local reactions such as redness, swelling, and pain at the injection site and less frequently caused systemic adverse events such as fever and prolonged crying," he said.
The QCMRI study looked at more than 40,000 Queensland children born in 1998 who were vaccinated against whooping cough.
It found that those treated with a full course of the newer acellular vaccine were three times more likely to have developed whooping cough in the current outbreak than those who received the previous whole cell vaccine.
"Looking at the bigger picture, it shows us that we don't yet have the perfect whooping cough vaccine and it gives us cause to work toward developing a more effective as well as a safe vaccine for whooping cough," Lambert added.
Whooping cough (or pertussis) is a highly contagious respiratory infection that begins with flu-like symptoms such as a blocked or runny nose, sneezing, mild fever and mild cough.
The findings were published in the Journal of the American Medical Association (JAMA).
