What are the latest guidelines for Tdap (Tetanus, diphtheria, and pertussis) and TT (Tetanus toxoid) vaccination in pregnancy?

Tdap and TT Vaccination in Pregnancy: Current Guidelines

All pregnant women should receive Tdap vaccine during each pregnancy between 27-36 weeks gestation, regardless of prior vaccination history, with earlier administration in this window (27-32 weeks) preferred to maximize maternal antibody transfer and infant protection. 1, 2

Core Recommendation

• Tdap should be administered during every pregnancy, even if the woman received Tdap previously, because maternal antibodies wane rapidly—women vaccinated in the first or second trimester show low antibody levels by term 3, 2
• The optimal timing is 27-36 weeks gestation, with vaccination earlier in this window (27-32 weeks) producing higher cord blood antibody concentrations 1, 2
• This timing allows at least 2 weeks for maximal immune response while ensuring active IgG transport occurs (which doesn't substantially begin until 30 weeks) 1
• Maternal Tdap vaccination is 80-91% effective in preventing infant pertussis and 58% effective in preventing hospitalization among infected infants 2

Special Clinical Situations

Tetanus Booster Due During Pregnancy

• If a woman is due for routine tetanus booster (>10 years since previous Td), administer Tdap instead of Td between 27-36 weeks gestation 3

Wound Management

• For wound management requiring tetanus prophylaxis (≥5 years since previous booster), give Tdap immediately regardless of gestational age—do not delay for the optimal window 3, 1
• The wound management indication supersedes the timing recommendation 4, 5

Unvaccinated or Unknown Vaccination Status

• Pregnant women with no prior tetanus vaccination require three doses: at 0,4 weeks, and 6-12 months 3
• Tdap should replace one dose of Td in this series, preferably administered between 27-36 weeks gestation 3, 2
• This ensures protection against both maternal and neonatal tetanus 3

Missed Opportunity During Pregnancy

• If Tdap was not given during pregnancy, administer immediately postpartum to reduce transmission risk to the newborn 3, 2, 6

Safety Profile

• Inactivated vaccines like Tdap show no evidence of adverse fetal effects during pregnancy 7, 6, 4
• Experience with tetanus toxoid-containing vaccines demonstrates no excess risk for severe adverse events with administration in every pregnancy 1
• The benefit of preventing infant pertussis morbidity and mortality outweighs theoretical concerns 1

Contraindications

• Severe allergic reaction (anaphylaxis) to a previous dose or vaccine component 2
• Encephalopathy within 7 days of previous pertussis-containing vaccine, not attributable to another cause 2

Cocooning Strategy

• Adolescents and adults with close contact to infants <12 months (parents, siblings, grandparents, caregivers, healthcare personnel) should receive one dose of Tdap if not previously vaccinated 3, 2
• This provides additional protection while the infant is too young for their own vaccine series 4, 5

Critical Pitfalls to Avoid

• Missing the 27-36 week window—this is when passive antibody transfer is optimized 1, 7
• Failing to vaccinate with each pregnancy—prior Tdap does not eliminate the need for vaccination in subsequent pregnancies due to rapid antibody waning 3, 2
• Delaying Tdap for wound management—give immediately when indicated, regardless of gestational age 3, 1
• Assuming prior vaccination is sufficient—the recommendation changed in 2013 to require vaccination with every pregnancy, not just once in a lifetime 6, 4

Implementation Considerations

• The American College of Obstetricians and Gynecologists and ACIP recommend that prenatal care providers implement Tdap immunization programs for all pregnant women 3, 2
• Provider recommendation is strongly associated with vaccine uptake—direct recommendation during prenatal visits is essential 8
• Current vaccination rates remain suboptimal (approximately 50-61%), indicating significant room for improvement 9, 8