A Randomized Controlled Trial of the Safety and Immunogenicity of Tetanus, Diphtheria, and Acellular Pertussis Vaccine Immunization During Pregnancy and Subsequent Infant Immune Response

Abstract

NCT00553228.

Safety of Maternal Immunization Against Pertussis: A Systematic Review

“…No significant increase in any of these outcomes were identified among infants of Tdap-vaccinated compared to non-vaccinated pregnant women, or from expected norms, regardless of design (database analysis vs. clinical trial), population, or setting [13,41,43,50,[52][53][54][55][56]58]. In addition, no differences in the rates of serious adverse outcomes were observed in infants of Tdap-and Td-vaccinated pregnant women, and none of the serious adverse outcomes reported were considered related to vaccination [35]. Hoang et al [36] reported that infants of Tdapvaccinated women presented common symptoms of respiratory and gastrointestinal diseases, although no events were serious or considered related to vaccination.…”

“…Injection site reactions assessed over 7 days were more common after Tdap than placebo in one small clinical study [13] but occurred at similar rates over 48 h in another slightly larger study [40]. Systemic and local reactions occurred at similar frequencies in pregnant women receiving Tdap and those receiving tetanus vaccines in two clinical studies [35,36]. For infants admitted to NICU, number of days in the unit (p = 0.001) and frequency of admission for preterm birth (p = 0.03) or anemia (p = 0.03) lower for Tdap vs.…”

“…Although Layton et al [43] found a small increase in postpartum hemorrhage in Tdap vaccinated compared with unvaccinated pregnant women (RR = 1.23; 95% CI 1.18-1.28) [43], the database analyses of Donegan et al [53] and Griffin et al [48] found no such increase with vaccination. ''Serious'' adverse pregnancy outcomes occurred at similar rates in Tdap-and Td-vaccinated pregnant women in a randomized prospective trial [35], and in Tdap plus influenza sequentially-or concomitantly-vaccinated pregnant women identified in an other database analysis [45].…”

“…Fifteen studies reported vaccine reactogenicity among pregnant women following immunization with Tdap or Tdap-IPV, among which nine were prospective clinical trials [13,[34][35][36][37][38][39][40][41] and six were database analyses [42][43][44][45][46][47] (Table 1). The most commonly reported reactions were injection site reactions, consistent with the Tdap label.…”

Immune interference (blunting) in the context of maternal immunization with Tdap-containing vaccines: is it a class effect?

“…We defined blunting as reported statistically significant lower GMC levels (based on non-overlapping 95% confidence intervals (CI) or p-values) against antigens included in DTaPcontaining vaccines when comparing immunogenicity in infants born to mothers who were vaccinated with Tdap-containing vaccines during pregnancy to a control group (infants born to mothers not exposed to Tdap during pregnancy) after primary immunization and/or booster dose. Of note, several papers reported significant p-values (p < 0.05) with overlapping 95% CI [19][20][21][22][23][24][25]. We adopted the approach to consider these papers as reporting statistically significant lower GMC levels between the two groups and provided point estimates and 95% CI (Table 2) for readers to make their own assessment whether the reported statistical significance refers to a real difference in GMC levels or haphazard reporting.…”