A study (11) indicated that the co-purified pertussis vaccines that are produced in China contain not only the main antigen of purified pertussis toxoid (PT), but also include filamentous hemagglutinin (FHA), pertactin (PRN), fimbriae (FIM) 2 and 3, and other minor protein antigens. The gene discussed is CIAO3; the disease is pertussis.