Immunogenicity of a liquid hexavalent DTaP-IPV-HB-PRPtiT vaccine after primary and booster vaccination of term and preterm infants born to women vaccinated with Tdap during pregnancy

Background: Vaccination during pregnancy with tetanus, diphtheria, acellular pertussis (aP) (Tdap) anti-gens is important for early protection of newborn infants against pertussis, particularly for preterm infants. This study evaluated the effect of Tdap vaccination during pregnancy on the immunogenicity of a diphtheria (D), tetanus (T), aP, inactivated poliovirus (IPV), hepatitis B (HB), and Haemophilus influen-zae type b (PRP ti T) vaccine in term and preterm populations.Methods: A prospective, observational study (NCT02511327) recruited women and their infants based on delivery (term or preterm) and vaccination status (vaccinated with a Tdap vaccine [BoostrixTM, GlaxoSmithKline] during pregnancy or not vaccinated in the last 5 years). All infants received licensed DTaP-IPV-HB-PRP ti T (HexyonTM, Sanofi) (8, 12, 16 week primary series and booster at 13 months of age [preterm infants] or 15 months of age [term infants]). Immunogenicity was evaluated using validated assays. Data were pooled into term (N = 127) and preterm infants (N = 105), and infants of women who received a Tdap vaccine during pregnancy (N = 199) or not (N = 33).Results: Before primary vaccination, antibody levels were higher for term than preterm infants for anti-D, anti-polio 1, 2, 3, anti-PT, anti-FHA, and anti-PRP, and similar for anti-HBs and anti-T. At this time, infants of Tdap-vaccinated women had higher anti-D, anti-T, anti-PT, anti-FHA, and anti-PRP antibody levels than infants of Tdap-unvaccinated women; anti-HBs and anti-polio antibody levels were similar in both groups. Post-primary, pre-booster, and post-booster, there were only small differences in seroprotection rates (anti-D, anti-T, anti-polio 1, 2, 3, anti-HBs, anti-PRP) and seroconversion rates (anti-PT, anti-FHA), except for anti-HBs >= 10 mIU/mL and anti-PRP >= 0.15 lg/mL post-primary vaccination (higher for term [98.31 % and 90.91 %, respectively] versus preterm infants [89.80 % and 79.41 %, respectively]).Conclusions: These data support the use of DTaP-IPV-HB-PRP ti T vaccine for primary and booster vacci-nation in term and preterm born infants and in infants born to Tdap-vaccinated or Tdap-unvaccinated women.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Publication year:2023

Keywords:A1 Journal article

Accessibility:Open