Maternal Immunization With Tetanus Toxoid, Reduced Diphtheria Toxoid, Reduced-dose (2 µg) Recombinant Pertussis Vaccine (TdaP2gen) and Its Effect on the Immune Response in Thai Infants up to 15-18 Months Old

Summary

Pertussis remains a major global public health problem. In Thailand, pertussis vaccination is recommended during pregnancy at 20-32 weeks' gestation, together with routine childhood diphtheria-tetanus-pertussis vaccination administered as a primary series at 2, 4, and 6 months and booster doses at 18 months and 4-6 years of age. TdaP2gen, a newly developed combined tetanus, diphtheria, and recombinant genetically detoxified acellular pertussis vaccine containing 2 µg pertussis antigen, has shown favorable safety and non-inferior immunogenicity compared with existing pertussis vaccines. However, data on its use in pregnant women, transplacental antibody transfer, and potential immune interference in infants remain limited. This study aims to evaluate the safety and immunogenicity of TdaP2gen in pregnant women, assess antibody transfer to newborns, and investigate immune responses to tetanus, diphtheria, and pertussis following primary and booster pertussis-containing vaccinations in infants and toddlers, including comparisons between whole-cell and acellular pertussis-containing vaccine schedules.

Timeline

Start

2026-05-26

Primary completion

2029-12-31

Completion

2030-12-31

Publications

• Background Chokephaibulkit K, Puthanakit T, Chaithongwongwatthana S, Bhat N, Tang Y, Anugulruengkitt S, Chayachinda C, Anuwutnavin S, Lapphra K, Rungmaitree S, Tawan M, Andi-Lolo I, Holt R, Fortuna L, Kerdsomboon C, Yuwaree V, Mansouri S, Thai PH, Innis BL. Effective and safe transfer of maternal antibodies persisting two months postpartum following maternal immunization with different doses of recombinant pertussis-containing vaccines. Vaccine. 2024 Jan 12;42(2):383-395. doi: 10.1016/j.vaccine.2023.11.042. Epub 2023 Dec 7.
• Background Puthanakit T, Chokephaibulkit K, Anugulruengkitt S, Chaithongwongwatthana S, Phongsamart W, Wittawatmongkol O, Rungmaitree S, Tang Y, Kerdsomboon C, Yuwaree V, Fortuna L, Mansouri S, Pham HT, Bhat N, Innis BL. Infant Responses to Primary Immunization Following Vaccination in Pregnancy With Varying Doses of Recombinant Acellular Pertussis Vaccine Alone or Combined With Tetanus-Diphtheria. Pediatr Infect Dis J. 2025 Feb 1;44(2S):S56-S60. doi: 10.1097/INF.0000000000004609. Epub 2025 Feb 14.

Drugs

Indications