Is the Tdap (Tetanus, diphtheria, and pertussis) vaccine safe during pregnancy?

Tdap Vaccination During Pregnancy: Safety and Recommendations

The Tdap vaccine is safe during pregnancy and is strongly recommended between 27-36 weeks gestation, preferably earlier in this window (27-30 weeks) to maximize antibody transfer and protection for the newborn. 1

Safety Profile

The Tdap vaccine has been extensively studied in pregnant women with no evidence of serious adverse events:

• No serious adverse events attributable to the vaccine have been reported in pregnant women 2
• Fever occurs in only 2.4%-6.5% of recipients, similar to rates in non-pregnant individuals 2
• The Advisory Committee on Immunization Practices (ACIP) has concluded that the potential benefit of preventing pertussis morbidity and mortality in infants significantly outweighs any theoretical concerns about adverse events 2
• Tetanus toxoid-containing vaccines have been used extensively in pregnant women worldwide with no reported clinically significant adverse events 2

Timing of Vaccination

The optimal timing for Tdap administration during pregnancy is:

• Between 27-36 weeks gestation 2, 1
• Preferably between 27-30 weeks for highest antibody concentrations in newborns 1, 3
• At least 2 weeks before delivery to allow for maximum immune response 2

Effectiveness

Maternal Tdap vaccination during pregnancy provides significant protection for newborns:

• 80-91% effective in preventing pertussis in newborns when administered at the recommended time 2, 1
• Reduces hospitalizations due to pertussis in infected infants by 58% 2, 1
• Vaccination at 27-30 weeks produces the highest antibody concentrations in newborns 4, 3
• Newborns of vaccinated mothers have significantly higher pertussis antibody levels (47.3 IU/mL vs 12.9 IU/mL in unvaccinated mothers) 4

Special Considerations

• If a tetanus booster is indicated during pregnancy (>10 years since previous Td), Tdap should be administered instead 2, 1
• If not administered during pregnancy, Tdap should be given immediately postpartum 2, 1
• For wound management during pregnancy, if tetanus prophylaxis is indicated, Tdap should be administered regardless of gestational age 1

Implementation Challenges

Despite strong recommendations, vaccination rates remain suboptimal:

• Only about 54.4% of pregnant women receive Tdap during pregnancy 5
• Vaccination rates increased from 13.8% in January 2013 to 51.0% in March 2014 following updated recommendations 6
• Women who receive a provider offer of vaccination have significantly higher vaccination rates than those who only receive a recommendation without an offer 5

Common Concerns and Misconceptions

• Some women decline vaccination due to concerns about vaccine effectiveness 5
• Many are unaware that Tdap is needed during every pregnancy, even if previously vaccinated 7, 5
• The risk of severe adverse events with repeated Tdap vaccination in closely spaced pregnancies is theoretical and not supported by evidence 2

Tdap vaccination during pregnancy is a critical strategy to protect vulnerable newborns from pertussis during their first months of life before they can begin their own vaccination series at 2 months of age. Healthcare providers should strongly recommend and offer Tdap vaccination to all pregnant women between 27-36 weeks gestation, with optimal timing between 27-30 weeks.