Title: Response to a DTaP-IPV-Hib combined vaccine (Pentaxim) Given as a Booster in Thai Children Primed with an Acellular Pertussis Combination Vaccine
Abstract:Background: We assessed the immune response to Pentaxim when given as a booster dose in Thai children primed with a diphtheria, tetanus, acellular pertussis, inactivated poliovirus, hepatitis B, Hib-c...Background: We assessed the immune response to Pentaxim when given as a booster dose in Thai children primed with a diphtheria, tetanus, acellular pertussis, inactivated poliovirus, hepatitis B, Hib-conjugate combination vaccine in infancy. Methods: DTaP-IPV-Hib vaccine (Pentaxim™, Sanofi Pasteur AcXim family vaccine) was given as a 4th (booster) dose at 18–24 months of age to 156 children previously primed at 2, 4 and 6 months of age with a hexavalent vaccine containing the same vaccine antigens plus hepatitis B. A dose of monovalent hepatitis B vaccine was also given at birth. Antibody titers were measured just before and one month after the booster vaccination. Reactogenicity and safety were evaluated from parent reports. Results: Seroprotection rates, approximately one year post-primary vaccination remained high. Anti-PRP GMT increased from 1.6 to 58.0 μg/mL pre- to post-booster vaccination. GMTs for PT and FHA increased from 3.8 to 181.2 EU/mL and from 18.0 to 289.7 EU/mL respectively. GMTs for each poliovirus type also strongly increased from pre- to post-booster dose. Vaccine reactogenicity was low. There were only two severe local reactions and two subjects had severe fever possibly related to vaccination, all of which resolved. Conclusion: Pentaxim induced a strong booster response to all the vaccine antigens at 18-24 months and was well tolerated. The timing of this booster was appropriate as pre-booster antibody titres and seroprotection rates remained satisfactory. Booster vaccination during from the second year of life has been recommended and is the practice in many different countries, with the aim of expanding control of childhood infectious diseases including pertussis and Hib. [study E2I36]Read More