The decision to switch to an acellular pertussis vaccine was in response to concerns raised regarding the side effects of whole cell vaccine (e.g. high fevers and febrile seizures). What is the vaccine effectiveness of acellular pertussis compared to whole cell vaccine? Zerbo et al. (10.1542/peds.2018-3466) performed a study we are early releasing this week in which they evaluated almost 470,000 children born into the Kaiser Permanente Northern California system between 1999 and 2016 and followed these children until they were age 11. They looked at immunization status and the incidence of pertussis. To no surprise, the results indicated that those who were under-vaccinated or not vaccinated had the greatest risk of getting pertussis (13 times higher for unvaccinated and 2 times higher for under-vaccinated), but more of a surprise was that 80% of the pertussis cases occurred in those furthest away from their last DTaP vaccine, raising concerns about the durability of protection.
What should we do about this? We asked Infectious Diseases specialist Dr. Kathryn Edwards (10.1542/peds.2019-1276) to provide an accompanying commentary to this study. Dr. Edwards recounts the evolution of the whole cell to the acellular vaccine and shares with us new ways on the horizon to deal with the waning immunity of DTaP demonstrated by this study. Take a shot at reading the study and commentary, and then keep your eyes focused on our journal and others as the studies to improve acellular vaccine efficacy are published.