As vaccine-induced immunity and protection following natural pertussis infection wane over time, adults and adolescents may develop pertussis and become transmitters to unprotected infants. In Russia, diphtheria and tetanus but not pertussis-containing vaccines are registered. The reduced-antigen-content diphtheria toxoid, tetanus toxoid, and dTpa vaccine for booster vaccination of children ≥four years of age, adolescents, and adults. A phase III, open-label, non-randomized study was performed in eight centers. The survey assessed immunogenicity, reactogenicity, and safety of a single dose of dTpa vaccine in healthy Russian participants under four. At 1-month post-booster vaccination, across all age groups, >99.0% of participants were seroprotected against diphtheria and tetanus, and >96.0% of participants were seropositive for anti-pertussis antibodies. Antibody GMCs increased from pre- to 1-month post-booster vaccination, and booster responses to diphtheria, tetanus and pertussis antigens were observed. One serious adverse event reported was not causally related to the study vaccine. There were no fatal cases throughout the study period. In conclusion, administering the dTpa vaccine as a booster dose in healthy Russian participants induced a robust immune response to all vaccine antigens. It was generally well tolerated across all age groups.

Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2020.1796423