In 1954, the diphtheria, tetanus, and whole-cell pertussis (DTwP) vaccine was introduced and used until the early 1980s, but due to the safety problems associated with the wP vaccine, an acellular pertussis (aP) vaccine containing pertussis toxoid (PT) and filamentous hemagglutinin (FHA) was developed [3]. Here, F2 is linked to pertussis.