Evaluation of several approaches to immunize parents of neonates against B. pertussis

Parental immunization ("cocooning") is a potentially effective strategy to protect neonates against Bordetella pertussis. The objective of this study was to evaluate three approaches to parental immunization: (1) current practice (single dTap dose to adolescents, one additional dose recommended in adults); (2) promotion of vaccination in the maternity ward, with vaccine offered in the community; and (3) promotion and administration of vaccine in the maternity ward.

We conducted a two-phase study of postpartum women in a tertiary care obstetric-pediatric hospital in Montreal, Canada. In Phase I, mothers completed a standardized questionnaire regarding pertussis knowledge, attitudes and immunization status. Interviews provided information on cocooning and pertussis vaccination, and invited parents to receive the vaccine in the community. In phase II, information was provided (no questionnaire) with vaccination offered in the maternity ward before discharge.

Phase I included 101 participants; Phase II, 244. Baseline knowledge on infant disease severity and adult vaccine recommendations was poor. Only 6% of women were considered protected. In Phase I, 56.3% and 62.5% of eligible mothers and fathers, respectively, were willing to receive the vaccine; only 5.4% and 8.7% were immunized in the community. In Phase II, 53.1% and 62.6% of mothers and fathers, respectively, would accept vaccination; 46.9% of mothers and 60.5% of fathers were immunized onsite (p<0.01).

Offering dTap vaccine in the maternity ward is an effective approach to promote cocooning and increase vaccine uptake. The generalizability and cost effectiveness of this strategy should be investigated further.