One such mRNA vaccine includes individual mRNA molecules encoding pertussis antigens: PTX-S1 (a truncated sequence from subunit S1 of pertussis toxoid), FHA3 (the C-terminal domain of filamentous hemagglutinin), FimD/Fim2/Fim3 (a fusion of several segments of proteins from different fimbrial serotypes), PRN, RTX (a repeat domain in toxin ACT), TCFA (tracheal cytotoxin factor A), SPHB1 (an autotransporter of subtilisin-like serine protease), and BRKA (a complement activation–inhibitory protein), as well as two mRNA molecules encoding the DT and TT antigen sequences [50]. Here, CIAO3 is linked to pertussis.