Researchers from The University of Queensland, in collaboration with the Telethon Kids Institute and Curtin University in Perth, and Menzies School of Health Research in the Northern Territory, have found that vaccinating pregnant mothers against whooping cough – otherwise known as pertussis – in their second or third trimester significantly reduced babies’ risk of infection.
Dr Lisa McHugh from UQ’s School of Public Health, said whooping cough is a highly contagious respiratory disease, but vaccination during pregnancy can prevent 70 to 90 per cent of hospitalisations and deaths in babies less than 6 months of age.
“The study examined data from 279, 418 mother and infant pairs, after the state vaccination program was introduced in 2014,” Dr McHugh said.
“Using health records from Western Australia, Queensland and the Northern Territory, 51 per cent of women in the study received a whooping cough vaccine around their late second trimester and third trimester of pregnancy.
“There were 331 cases of pertussis among the cohort, with 119 cases among infants of vaccinated mothers and 212 among infants of unvaccinated mothers.
“The severity of infection also tended to be worse in cases where the mother was unvaccinated, with infants three times more likely to need hospitalisation and twice as likely to require admission to intensive care.”
It is currently recommended that mothers receive the vaccine at around 20-28 weeks’ gestation, along with the routinely recommended childhood vaccinations to provide maximum protection against pertussis infections.
Professor Hannah Moore, co-author and epidemiologist from Curtin University’s School of Public Health said the study’s results supported current recommendations and confirmed that vaccination for mothers at 20 to 28 weeks gestation delivers the highest protection for babies up to six months old – the most susceptible period for infection.
“We also found that the maternal vaccine reduced the effectiveness of babies’ third whooping cough vaccine dose, but this was not associated with an increase in infections; meaning there were still enough antibodies to protect infants and fight infection,” Dr Moore said.
The research was supported by funding from the National Health and Medical Research Council and the Western Australian Department of Health.
The research is published in Pediatrics.
Media: UQ Faculty of Medicine, med.media@uq.edu.au , +61 436 368 746.
