However, since the aP vaccine antigens PT, PRN and FHA are also expressed by B. pertussis during infection, infection with B. pertussis in aP-primed individuals may not only lead to de novo formation of memory B and T cells against non-vaccine antigens, but also activate pre-existing aP antigen-specific memory B and T cells. The gene discussed is DHCR7-DT; the disease is infection.