There are several explanations for the rise in pertussis, but the most likely is waning immunity after vaccination. “Immunity wears off, especially for adults who are decades past their most recent vaccination,” said Dr. Tom Clark, an epidemiologist with the C.D.C.
Moreover, adults and adolescents often wait weeks before seeking treatment for a chronic cough — and even then, doctors may not recognize it as pertussis.
This is especially important to note for parents of infants. Tara Parker-Pope talks about almost reaching for the phone to call 911 because her 11-year-old daughter's coughing fits are so frightening. For an infant, pertussis can mean far more serious illness including weeks of hospitalization - but they're harder to protect because they can't be fully immunized for months.
One way to protect them is for all the adults and older children who regularly come in contact with them to update their pertussis vaccinations, so that those people can't transmit it to the baby. The pertussis vaccine is often given in combination with the tetanus vaccine now; check to see if you've had a "Tdap" shot in the past few years.
The hospital where I work, and many pediatricians' offices, are now checking with parents about their immunization status - but if yours doesn't, make sure you do it on your own! And if someone else (relative, friend, etc.) is regularly coming in contact with your baby, ask them to check their immunization status too. I encourage doulas and anyone else who regularly comes into contact with moms and babies to do the same, to protect their clients. I got a Tdap update when I started working at the hospital. I didn't love the sore arm, but it was worth it. And that's your public health message of the day!