F2 and diphtheria: In addition to the traditional antigens, PT, FHA, PRN, and Fim2/3, the new antigens explored (such as BF, BipA, ACTΔ, etc.)as well as OMV pertussis vaccines have the potential to be used in combination with tetanus and diphtheria vaccines, turning them into the novel pertussis–diphtheria–tetanus combined vaccines [65,67,73,81].