BACKGROUND: Pertussis is the most commonly reported vaccine preventable disease in children younger than 5 years in the United States. Newborns and infants too young to be vaccinated (<2 months) against pertussis are at the highest risk for severe morbidity and death from pertussis. With several recent pertussis outbreaks and a rise in the proportion of incident pertussis among adolescents in Washington State, there is a need to evaluate whether teen mothers are receiving recommended pregnancy-related Tdap vaccinations to protect both themselves and their child from the disease.
METHODS: This analysis linked Washington State birth certificate data and Washington Immunization Information System (WIIS) records. All mothers of babies born in Washington State between July 1, 2005 and June 30, 2015 that were 18 or under at time of delivery were included in the study. Receipt of Tdap by the mother according to the Advisory Committee on Immunization Practices (ACIP) Tdap recommendation in place at the time of birth was examined for all babies born during the study period.
RESULTS: A total of 30,578 mothers <18 gave birth to 32,504 babies during the 10 year period. Maternal ages ranged from 11 to 18 years with an average age of 17 years. About three quarters of the mothers (24,004 or 78.5%) could be matched to WIIS records. Of those, 15,471 (64.5%) had received at least 1 Tdap. Of mothers with any Tdap receipt, just under a third (4,558 or 29.4%) met the ACIP Tdap recommendation in place at the time of birth for one or more of their children. Among 28.3% of all births during the study period, the delivering mother met the ACIP Tdap recommendation in place at the time.
CONCLUSIONS: This analysis examined receipt of Tdap vaccine according to ACIP recommendations for pregnant women in a population for whom all childhood and adolescent vaccines are universally provided. Although Tdap doses may not be reflected in WIIS for those born or raised outside of Washington, the results of this study suggest that additional efforts to reach the special population of young women who become pregnant during their teens may be indicated.