Whooping cough (pertussis) often begins like a cold but then progresses to a severe cough punctuated by sharp breath intakes resembling “whoops.” This extremely contagious condition is caused by the bacterium Bordetella pertussis and can be fatal in newborns.

Pertussis was thought eradicated in the United States following the introduction of a vaccine in the 1950s. At that time, children received the wP (“whole-cell”) vaccine, which was effective but phased out due to rare side effects. By the mid-90s the dominant pertussis vaccine was an “acellular” (aP) form, now administered in childhood as a vaccine combination called DTaP (diphtheria, tetanus and acellular pertussis). Today, most pertussis vaccine protocols involve five injections in early childhood, and then children at 11 and 12 years old receive a booster, as do pregnant women and adults at risk for whooping cough.

However, in 2010, California health officials reported a pertussis epidemic and began fearing whooping cough re-emergence, partly due to some parents’ decision to opt out of childhood immunizations (despite ample evidence of safety). By 2015, over 20,000 pertussis cases had been reported nationwide, many occurring in teenagers originally vaccinated with the aP vaccine. Since then, many researchers, including those at LJI, have been closely comparing immunity conferred by the aP versus wP forms of the vaccine, and asking how to build a novel vaccine that would be both safe and effective.