Widespread vaccination of adolescents for pertussis was associated with fewer-than-expected hospital stays for infants affected by this dangerous respiratory infection, according to findings published online Oct. 21 in Pediatrics.

Investigators from Cincinnati Children’s and the University of Michigan compared pertussis hospitalization rates for infants before and after 2006, when the Centers for Disease Control and Prevention (CDC) recommended pertussis vaccines for all teens.

In three of the four years examined after the teen vaccination recommendations (2008-2011), investigators found lower hospitalization rates for infants than would have been expected with no adolescent vaccinations.

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 3.27 hospitalizations per 10,000 infants.

 These findings underscore the importance of increasing vaccination rates among teens and adults to stem an ongoing pertussis epidemic among infants, says Katherine Auger, MD, MSc, the study’s lead author and a pediatrician in Division of Hospital Medicine.

“We know infants get pertussis from family members, including older siblings,” Auger said. “While it is encouraging to find a modest reduction in infant hospitalizations after the vaccination of adolescents began, there were still more than 1,000 infants hospitalized for pertussis in 2011. Expecting parents should discuss with their doctors the need for vaccination of all caregivers before the birth of a baby.”

In addition to teens, all pregnant women should receive pertussis vaccination during pregnancy, according to a 2012 CDC recommendation.  Auger says future research will explore how this policy change affects pertussis hospitalization rates in infants.

Article written by Nick Miller, Cincinnati Children’s. Contact: Nicholas.Miller@cchmc.org