Clinical Edge

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Reactogenicity & Immunogenicity of Tdap in Pregnancy

Vaccine; ePub 2018 Sep 13; Fortner, et al

Tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine was well-tolerated in both pregnant and nonpregnant women, with pain at injection site more likely in pregnant women, a recent study found. Researchers compared local injection-site and systemic reactions and serologic response following Tdap in pregnant women (gestational age 20-34 weeks) and nonpregnant women and in pregnant women by self-reported prior Tdap receipt. Injection-site and systemic reactions were assessed for 1 week post-vaccination. They found:

  • 374 pregnant and 225 nonpregnant women were vaccinated.
  • Severe local or systemic reactions or “any” fever were uncommon in both groups.
  • Moderate/severe injection-site pain was significantly higher in pregnant vs nonpregnant women (18% vs 11%) but did not necessitate a healthcare visit.
  • Prior Tdap receipt did not increase occurrence of moderate/severe local or systemic reactions in pregnant women.
  • Serologic responses to all vaccine antigens were robust.


Fortner KB, Swamy GK, Broder KR, et al. Reactogenicity and immunogenicity of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) in pregnant and nonpregnant women. [Published online ahead of print September 13, 2018]. Vaccine. doi:10.1016/j.vaccine.2018.07.012.


This study highlights that the Tdap vaccine is very well tolerated. The side effect of local pain is a very well-expected phenomenon. The side effect was more common in pregnant women in this study, but this localized tenderness was mild and transient. The study showed that the vaccine had a good immune response which is important if we will give this vaccine every pregnancy to protect newborns from tetanus and pertussis. —John Russell, MD