More information on Tdap vaccinations
The American College of Obstetrics and Gynecology and the Advisory Committee on Immunization Practices now recommends that all pregnant women receive the Tdap vaccine during each pregnancy. This is an update from previous recommendations.
The optimal time to receive the vaccine is between 27 and 36 weeks gestation. The rationale for changing the recommendation is discussed in the excerpt from the ACOG Committee Opinion on the subject.
Excerpt from ACOG, update on immunization and pregnancy (Tdap)
The overwhelming majority of morbidity and mortality attributable to pertussis infection occurs in infants who are less than or equal to 3 months of age. Infants do not begin their own vaccine series against pertussis (with the diphtheria, tetanus and acellular pertussis vaccine) until 2 months of age. This situation leaves a window of significant vulnerability for newborns, many of whom appear to contract serious pertussis infections from family members and caregivers, including the mother.
Starting in 2006, the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC) recommended an approach to combat neonatal pertussis infection referred to as “cocooning.” This approach essentially consisted of a recommendation to administer Tdap to all women in the immediate postpartum period and all other family members and caregivers who had not previously received the vaccine in order to provide a protective cocoon of immunity around the newborn.
This approach has proved challenging and insufficient when used alone at preventing neonatal pertussis infections for a variety of reasons. Importantly, cocooning leaves vulnerable infants without any endogenous protective antibody until they begin their own vaccine series at 2 months of age. Thus, they are solely dependent on the immunity of those around them for pertussis protection in the critical first 2–3 months of life.
In June of 2011, the ACIP considered this situation and issued a new recommendation that pregnant women who had not previously received a dose of Tdap should receive it during pregnancy (preferably after 20 weeks of gestation). The recommendation suggested that the third trimester or the late second trimester would be optimal timing for the administration of Tdap. Additionally, the ACIP stated that women who did not receive Tdap during pregnancy should still be immunized in the immediate postpartum period, along with all others who will have close contact with the newborns (sustained efforts at cocooning). Preliminary data on this new approach suggests that uptake of the maternal immunization recommendation has been suboptimal (2.6%), although robust data are not yet available.
The ACIP again reconsidered this topic in October 2012 in the face of dramatic and persistent increases in pertussis disease in the United States. Issues considered included an imperative to minimize the significant burden of disease in vulnerable newborns, the reassuring safety data on use of Tdap in adults, and the evolving immunogenicity data that demonstrate considerable waning of immunity after immunization. The ACIP published its updated recommendation in February 2013, which recommends that health care personnel administer a dose of Tdap during each pregnancy, irrespective of the patient’s prior history of receiving Tdap. To maximize the maternal antibody response and passive antibody transfer and levels in the newborn, optimal timing for Tdap administration is between 27 weeks and 36 weeks of gestation, although Tdap may be given at any time during pregnancy.
Receipt of Tdap at some point during pregnancy is critical, and there may be compelling reasons to vaccinate earlier in pregnancy (see examples under “Special Situations During Pregnancy). For women who previously have not received Tdap, if Tdap was not administered during pregnancy, it should be administered immediately postpartum to the mother in order to reduce the risk of transmission to the newborn. Additionally, other family members and planned direct caregivers also should receive Tdap at least 2 weeks before planned infant contact, as previously recommended (sustained efforts at cocooning). The American College of Obstetricians and Gynecologists’ (the College) Committee on Obstetric Practice supports these revised recommendations. Given the rapid evolution of data surrounding this topic, immunization guidelines are likely to change over time, and the College will continue to issue updates accordingly.
The complete Committee Opinion can be read on the American College of Ob/Gyn website.