Australia is currently experiencing an increase in pertussis notifications. There were 22,325 notifications in 2015, almost double that of the previous year. Pertussis is a highly communicable respiratory infection with significant morbidity and, in infants, mortality.
The Australian Immunisation Handbook now recommends pertussis vaccination during the third trimester of each pregnancy. A recent study of 408 infants born to mothers who received the pertussis vaccination during pregnancy supports this recommendation. No cases of pertussis occurred in this cohort during the six-month follow-up, despite high rates of disease in the community. In addition, no safety concerns were identified during the study.
The optimal time for antenatal pertussis vaccination is between 28 and 32 weeks gestation. Active transport of maternal antibodies to the foetus mainly occurs after 30 weeks, and it takes around two weeks for antibody levels to peak post-vaccination. These maternal antibodies provide direct passive immunity to the newborn until primary vaccination can occur at six to eight weeks of age.
Immunity from vaccination and natural infection wanes over time, so vaccination is recommended during each pregnancy. It is also prudent for new fathers to consider a booster dose, as well as other household contacts of newborns, childcare workers, and healthcare workers.
- Australian Government Department of Health. The Australian Immunisation Handbook (10th edition). Canberra: Commonwealth of Australia; 2015.
- Walls T, Graham P, Petousis-Harris H, Hill L, Austin N. Infant outcomes after exposure to Tdap vaccine in pregnancy: an observational study. BMJ Open. 2016; 6(1): e009536.