What is the Tdap vaccine?
Tdap is a combination vaccine that protects against 3 bacterial infections in a single injection: Tetanus, diphtheria, and pertussis. The 3 vaccine components are tetanus (T) and diphtheria (d) and acellular pertussis (ap), which provides protection against pertussis infection. There is no live vaccine component in Tdap as it is manufactured using inactivated non-infectious bacterial products that generate a robust immune response. This vaccine has been recommended since 2005 for adolescents and adults.
Has Tdap vaccine been given to pregnant and postpartum women before and why?
Yes. Since 2005 a dose of Tdap vaccine has been recommended for any previously unvaccinated postpartum woman and all household members who come into contact with newborns to protect newborns from neonatal pertussis (“whooping cough”), a serious and potentially fatal disease that continues to affect infants in the US. This approach, which also protects the mother herself, has been referred to as “cocooning,” since it provides a protective “cocoon” around the newborn by preventing pertussis in mothers and other household members, who, it has been shown, are the individuals most likely to transmit this infection to the baby.
In June of 2011, the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC) recommended that pregnant women receive Tdap vaccination during the second half of pregnancy, partly because the efforts at cocooning alone did not provide sufficient protection for newborns. Thus, since that recommendation was published many pregnant women have begun to receive Tdap vaccine during pregnancy. Additionally, in special situations, such as maternal exposure to pertussis during pregnancy and outbreak situations, many pregnant women received Tdap prior to the June 2011 ACIP recommendation.
Why is it now necessary to vaccinate pregnant women?
Cocooning programs have proven difficult to implement, and infant pertussis continues to cause morbidity and mortality. Even with previous maternal vaccination, the most significant challenge of cocooning is the obstacle represented by unimmunized family members, which leaves the neonate vulnerable to infection.
In February and June 2011, the ACIP reviewed the available data regarding the impact of pertussis on infants, the barriers to implementation and effectiveness of cocooning programs, the safety of Tdap vaccine given to pregnant women, the potential benefits of transplacental antibody from mother to fetus to provide direct passive protection to the neonate, the length of time that antibody persists after immunization in the mother and newborn, and the cost-effectiveness of maternal immunization (immunizing pregnant women for the benefit of themselves and their fetus/newborn) and recommended a dose of Tdap for pregnant women who never received Tdap. In October 2012, ACIP reviewed data on persistence of maternal pertussis antibodies which indicated that maternal antibodies from Tdap at one pregnancy would be insufficient to provide protection for subsequent pregnancies, and therefore ACIP updated the recommendation. The revised and current recommendation is that all pregnant women receive Tdap during each pregnancy, regardless of the interval since the last tetanus toxoid-containing booster. Tdap should be given during each pregnancy, preferably during weeks 27-36 gestation. A good strategy is to give Tdap vaccine at 28 weeks, at the same visit the glucose screening test is done in order to help work flow and maximize Tdap immunization. There is no contraindication to giving Tdap vaccine at same visit as Rhogam.
Why was “during 27-36 weeks” chosen as the preferred time for maternal immunization?
Targeting the last trimester of pregnancy was decided upon in an effort to to maximize the high-level antibody transfer to the fetus later in gestation to optimize potential newborn protection.
What if a pregnant woman who has never been vaccinated with Tdap does not receive a dose of Tdap during her pregnancy?
She should receive the dose of Tdap in the immediate postpartum period, preferably prior to discharge after delivery.
Should a postpartum woman who did not receive the Tdap vaccine during pregnancy but received a dose in the past (that is documented in her medical record) be immunized postpartum?
She would not need to receive the Tdap vaccine postpartum. Tdap vaccine is recommended during each pregnancy but not during each postpartum period. The best protection for the infant is for the woman to get Tdap vaccination during pregnancy to provide protective antibodies at the time of delivery. Tdap should be administered immediately postpartum for women not previously vaccinated with Tdap and if Tdap was not administered during pregnancy.
What if a woman requires a tetanus and/or diphtheria booster during pregnancy for any other reason, such as wound care?
She should receive a single dose of Tdap at that time in place of the tetanus/diphtheria booster. Tdap is considered safe to give, when indicated, at any time during gestation. In this clinical scenario of acute wound management, less emphasis should be given to the recommended optimal timing window of 27-36 weeks of gestation.
If there is a local community outbreak of pertussis, what is recommended for a pregnant woman?
She should receive a Tdap immunization as soon as possible. In this clinical scenario less emphasis should be given to the recommended optimal timing window of 27-36 weeks of gestation. Tdap is considered safe to give when indicated at any time during pregnancy. If she has been exposed to pertussis, she should be evaluated by her provider, and may also receive antibiotic chemoprophylaxis. Other family members should also receive Tdap immunization for protection against the local outbreak after discussing with their respective health-care providers.
Are there any circumstances when a woman would receive Tdap earlier than 27-36 weeks in pregnancy?
Tdap is preferred to be given during 27-36 weeks gestation, but may be given before 27-36 weeks gestation in certain circumstances such as during a community outbreak. Tdap is considered safe to give when indicated at any time during gestation. Pregnant women who require a tetanus booster for wound contamination should receive Tdap.
If a pregnant woman is vaccinated early in her pregnancy (ie before 27-36 weeks gestation), does she need to be vaccinated again during 27-36 weeks gestation?
No. Women should receive 1 dose of Tdap during each pregnancy.
What if a woman becomes pregnant again soon after she received Tdap in her previous pregnancy?
According to the current ACIP guidelines women should receive Tdap in each pregnancy. This recommendation stands regardless of the timing of the last Tdap immunization.
What should we do about cocooning?
Regardless of when a mother receives Tdap, efforts should be made to also assure that all family members and caregivers who will have close contact with the newborn also receive a dose of Tdap, to continue to provide the protection of cocooning. Health care providers should recommend Tdap vaccination of family members (cocooning) during prenatal care visits and at the time of delivery. Ideally, the mother and all family members should be vaccinated at least 2 weeks prior to coming in contact with the newborn baby.
Should providers continue to offer Tdap as part of routine preconception care?
No, Tdap is no longer encouraged during preconception visits. The best time to administer Tdap to your patients who are pregnant or are trying to conceive is at 27-36 weeks gestation of each pregnancy. Providers may consider postponing preconception Tdap vaccination but if Tdap is administered at a preconception visit (for example, if pertussis is circulating in the patient’s community), Tdap should be administered again during pregnancy at 27-36 weeks gestation in order to provide optimal protection to the baby during its first months of life.
1. Update on immunization and pregnancy: tetanus, diphtheria, and pertussis vaccination. Committee Opinion No. 566. American College of Obstetricians and Gynecologists. Obstet Gynecol 2013;121:1411-4
2. Updated recommendations for use of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine from the Advisory Committee on Immunization Practices, 2010. Centers for Disease Control and Prevention (CDC). MMWR Morb Mortal Wkly Rep 2011;60:13-5
3. Updated recommendations for use of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine (Tdap) in pregnant women and persons who have or anticipate having close contact with an infant aged <12 months --- Advisory Committee on Immunization Practices (ACIP), 2011. Centers for Disease Control and Prevention (CDC). MMWR Morb Mortal Wkly Rep 2011;60:1424-6