Recent pertussis epidemics have triggered implementation of cocooning, involving caregiver vaccination to indirectly protecting susceptible infants.

To determine patient, provider and setting factors associated with maternal pertussis booster vaccination (dTpa) within 5–10 years before childbirth.

Materials and Methods
Cross‐sectional survey using Health Belief Model constructs among postpartum women in a tertiary referral centre and a private hospital in Sydney, Australia.

Pertussis vaccination was current among 33.7% of the 2483 new mothers (0.5% vaccinated during pregnancy). Women were more likely to be vaccinated if they had heard of ‘whooping cough’ from a health professional (OR: 2.59, P < 0.001, 95% CI: 1.70–3.95), were recommended the vaccine (OR: 2.48, P < 0.00, 95% CI: 1.55–4.00), perceived pertussis as ‘severe’ for adults (OR: 1.21, p0.009, 95% CI: 1.05–1.39) and ‘common’ within their community (OR: 1.38, P < 0.001, 95% CI: 1.18–1.61). They more often agreed that it was their parental responsibility to be vaccinated (OR: 1.61, P = 0.002, 95% CI: 1.19–2.18), and this would help prevent their baby from contracting pertussis (OR: 1.22, P = 0.046, 95% CI: 1.00–1.47). Vaccinated women were less likely to report vaccination barriers: time constraints (OR: 0.75, P < 0.001, 95% CI: 0.66–0.85) and having safety concerns (OR: 0.80, P < 0.001, 95% CI: 0.69–0.92). Additionally, their partners reported three times higher uptake (76% vs 49%; P < 0.001; 95% CI: 2.66–3.85). Conclusions Current pertussis vaccination in only one in every three postpartum participants may indicate insufficient coverage to protect newborns. Practitioners are instrumental in raising awareness and addressing vaccine concerns. Integrating vaccination into routine obstetric care, whether antenatally or postnatally, may minimise barriers.