Cocooning to protect infants from pertussis

Recent studies on cocooning to protect infants from pertussis

Evaluation of the impact of a pertussis cocooning program on infant pertussis infection.

Healy CM, Rench MA, Wootton SH, Castagnini LA. 2015

Postpartum immunization and cocooning did not reduce pertussis illness in infants ≤6 months of age. Efforts should be directed toward increasing tetanus, diphtheria and acellular pertussis immunization during pregnancy, combined with cocooning, to reduce life-threatening young infant pertussis.

Impact of maternal postpartum tetanus and diphtheria toxoids and acellular pertussis immunization on infant pertussis infection. 

Castagnini LA, Healy CM, Rench MA, Wootton SH, Munoz FM, Baker CJ. 2012

It was disappointing—but not surprising, given the likelihood of contact with other pertussis-infected individuals—that we were unable to demonstrate any
impact of this program on the occurrence of pertussis in infants.

Acellular pertussis vaccines protect against disease but fail to prevent infection and transmission in a nonhuman primate model

Jason M. Warfel, Lindsey I. Zimmerman, and Tod J. Merkel 2013

Consistent with these findings, seroepidemiological studies have concluded that B. pertussis circulation is still high in countries with excellent aP uptake (27, 50), and a cross-sectional study showed that postpartum aP vaccination of mothers did not reduce pertussis illness in young infants (51). These data suggest that cocooning is unlikely to be an effective strategy to reduce the burden of pertussis in infants.

The impact of parental postpartum pertussis vaccination on infection in infants: A population-based study of cocooning in Western Australia.

Carcione D, Regan AK Tracey L Mak DB, Gibbs R, Dowse GK, Bulsara M, Effler PV. 2015

There was no difference in the incidence of pertussis among infants whose parents were both vaccinated postpartum compared to those with unvaccinated parents

Cost-benefit of the introduction of new strategies for vaccination against pertussis in Spain: cocooning and pregnant vaccination strategies. 

Fernández-Cano MI, Armadans Gil L, Campins Martí M 2015

The number of parents needed to vaccinate with the cocoon strategy to prevent 1 pertussis hospitalization would be 4752 and to prevent 1 death, more than 900,000. With VPW, 1331 pregnant women would have to be vaccinated to prevent 1 hospitalization and 200,000 to prevent 1 death. The benefit-to-cost ratio was 0.04 for cocooning and 0.15 for VPW.

Finding the ‘who’ in whooping cough: vaccinated siblings are important pertussis sources in infants 6 months of age and under. 2014
Bertilone C, Wallace T, Selvey LA.

At its peak, siblings were the most important sources of pertussis in infants 6 months and younger, particularly fully vaccinated children aged 2 and 3 years. Waning immunity before the booster at 4 years may leave this age group susceptible to infection. Even if cocooning programs could achieve full vaccination coverage of parents and ensure all siblings were fully vaccinated according to national schedules, waning immunity in siblings could provide a means for ongoing transmission to infants.