Protecting Infants from Whooping Cough
Katherine A. Auger, MD, MSc, a pediatrician in the Division of Hospital Medicine, Department of General Pediatrics at Cincinnati Children’s Hospital Medical Center, is an alumna of the Robert Wood Johnson Foundation (RWJF) Clinical Scholars program.
A 2006 recommendation from the Centers for Disease Control and Prevention (CDC) that all adolescents receive vaccines for pertussis, also known as whooping cough, is having a positive impact. A new study that I led shows it is associated with lower rates of infant hospitalizations for the respiratory infection than would have been expected had teens not been inoculated.
The study, published in Pediatrics, found that the CDC recommendation led not only to a significant increase in vaccination rates among teens, but also to a reduction in severe pertussis-related hospitalizations among infants, who often catch the disease from family members, including older siblings.
The incidence of pertussis in this country had been on the rise for the past decade due to waning immunity (which occurs five to ten years after the vaccine is administered) and failure to vaccinate.
For older children and adults, pertussis begins as a cold but then becomes a chronic severe cough that can last for months. Infants, however, can become seriously ill from pertussis. They often require hospitalization to monitor for apnea, a life-threatening pause in breathing.
The research team from Cincinnati Children’s Hospital Medical Center and the University of Michigan examined pertussis hospitalization rates for infants before and after the CDC issued the new adolescent vaccine recommendations. We used hospitalization data from 2000 to 2005—prior to the teen vaccination recommendation—to predict hospitalization rates had adolescent vaccinations not been implemented.
In 2011, for example, the expected hospitalization rate for pertussis if adolescent vaccinations had not been implemented was 12 hospitalizations per 10,000 infants. The observed rate following the teen vaccinations was significantly lower at just 3.27 hospitalizations per 10,000 infants.
We also found decreases in the expected number of hospitalizations in three of the four post-vaccine years we examined (2008-2011).
This finding is striking in the context of the overall increase in the number of pertussis cases nationally. This study is one of the first to demonstrate a benefit to infants by vaccinating people around them. It suggests this recommendation is working well, and that infants can be healthier if we continue to vaccinate the people around them.
Study authors received funding from RWJF through its Clinical Scholars program.