Professor Arthur Reingold is Head of Epidemiology at UC Berkeley’s School of Public Health California: Is whooping cough coming back? We certainly are having a resurgence of pertussis in the United States, although it’s never gone away. It is a threat to very young infants, particularly those too young to be vaccinated or who have not yet had a complete series of the vaccines. Where does pertussis come from? How can you catch it?