Magnitude of Interference after Diphtheria‐Tetanus Toxoids–Acellular Pertussis/Haemophilus influenzaeType b Capsular Polysaccharide–Tetanus Vaccination Is Related to the Number of Doses Administered

Abstract

We compared the antibody response to Haemophilus influenzae type b capsular polysaccharide (PRP) after 1, 2, or 3 doses of a diphtheria-tetanus toxoids-acellular pertussis (DTaP) vaccine combined with a PRP-tetanus conjugate (PRP-T) vaccine, followed by separate injections of DTaP and PRP-T vaccines for the last 1 or 2 doses. Healthy infants were recruited from pediatric practices and were immunized according to recommended schedules. A significant decrease in the mean anti-PRP (from 5.25 to 2.68 microg/mL) and anti-tetanus toxoid antibody responses (from 0.13 to 0.09 Eq/mL) was observed as the number of doses of the DTaP/PRP-T combination vaccine increased (P<.02 and P=.01, respectively). In contrast, the mean anti-diphtheria toxoid antibody response increased with increasing numbers of DTaP/PRP-T doses (P=.0001). The effects of interference were not eliminated by the completion of the primary series with 1 or 2 doses of the DTaP and PRP-T vaccines given separately.

Fall in Haemophilus influenzae serotype b (Hib) disease following implementation of a booster campaign

“…A case–control study at that time showed that a higher proportion of children with Hib vaccine failure had received three doses of DTaP-Hib vaccine for their primary immunisation schedule compared with vaccinated controls who had not developed invasive Hib disease 29. Furthermore, there was a trend for an increased risk of vaccine failure with each additional dose of the DTaP-Hib vaccine, an observation confirmed by a second study 30. In a separate study, analysis of vaccine effectiveness using the screening method also showed reduced vaccine efficacy in children immunised between 2000 and 2002, when the DTaP-Hib vaccine was in circulation 21…”

Kinetics and Avidity of Antibodies Evoked by Heptavalent Pneumococcal Conjugate Vaccines PncCRM and PncOMPC in the Finnish Otitis Media Vaccine Trial

“…Various DTaP-Hib vaccines, containing acellular pertussis components, have been associated with reduced Hib immunogenicity compared to DTwP vaccines (15,18), but the clinical importance of this finding is unclear. The whole-cell pertussis vaccine might also serve as an adjuvant when PCVs are administered.…”

Vaccine responsiveness in premature infants

“…as an example of lack of pertussis adjuvanticity. [16][17][18][19] Berrington et al reported that anti-PRP antibody titres were also lower when premature infants were administered polio vaccine as eIPV. 13 Baxter et al in a prospective pragmatic case series study of premature infants ≤32 weeks given DTaP-Hib and MenC or DTwPHib and Men C using a 2, 3 and 4 month schedule and reported in this issue of Human Vaccines found that just over one third (34.7%) had an anti-PRP level >1.0 µg/ml with a similar proportion (32.2%) of infants having a non detectable antibody level.…”