Pertussis, or whooping cough, is a severe, potentially life-threatening disease caused by the bacteria Bordetella pertussis and is one of the most prevalent vaccine-preventable diseases in the United States.¹ The classic presentation of pertussis occurs in unvaccinated children younger than 10 years who develop paroxysms of cough followed by forced inspiratory efforts (a whoop) and posttussive emesis.² The coughing spells may lead to gagging, apnea, and cyanosis. Older children and adults often experience mild or asymptomatic disease. Continued outbreaks of pertussis may be due to several factors, including lower vaccination rates, waning immunity in previously vaccinated adolescent and adult populations, and genetic changes in the circulating strains of pertussis.^3,4