In this issue of American Family Physician, Gregory1 gives an excellent up-to-date summary of the epidemiology, natural history, clinical presentation, laboratory diagnosis, and guidelines for treatment of pertussis.1 For more than a decade, this bacterial respiratory disease has stood out among other vaccine-preventable diseases by simply refusing to go away. Measles, rubella, and Haemophilus influenzae meningitis have retreated in the footsteps of smallpox, diphtheria, and polio. These diseases are so rare in the United States that today's physicians need special training to recognize them. Meanwhile, children, adolescents, and adults continue to get pertussis, which causes coughing, suffering, and loss of valuable work time. These patients then transmit the infection to vulnerable infants.2
Why is this happening? Whole-cell pertussis vaccine, one of the first to be routinely recommended for children, effectively protected children (after the third dose) from about six months of age well into the school-age years. Acellular pertussis vaccine, introduced in the mid-1990s, has been at least as effective and has a more favorable safety record. Unfortunately, infants are too young to have completed their vaccinations and do not have the same level of maternal antibody protection for pertussis as they do for other diseases (e.g., measles, varicella), leaving them susceptible. Increasingly, physicians and epidemiologists have recognized that adolescents and adults, especially those living with an infant, are the most likely sources of pertussis transmission to infants.3,4 As laboratory diagnosis of pertussis has improved over the past two decades, it has become possible to more accurately document pertussis in adults who present without classic symptoms and signs. Thus, we can now show what we previously only suspected—adults are the sources of infection.
As Gregory1 notes, two new tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines (Boostrix and Adacel) recently were approved for use in adolescents and adults. The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics, and the American Academy of Family Physicians have recommended replacing the routine tetanus-diphtheria (Td) booster with the Tdap vaccine for adolescents and adults up to 64 years of age.5–7 We now have the tools to interrupt the cycle of pertussis transmission, thereby saving the lives of more infants and young children.
Gregory1 clearly outlines that pertussis continues to be a serious illness that is much easier to prevent than to diagnose and treat. Our purpose is to add a clear call to action: family physicians must make sure that their patients receive the new Tdap vaccine on the recommended schedule. The strategy is simple logistically, because it replaces an existing dose rather than adding a new one. The routine interval is 10 years between doses. Intervals as short as two years for catch-up in adolescents or adults who have not received previous Tdap vaccination are outlined in recently published ACIP recommendations.6,7 We should quickly take this next step to push pertussis into history.