Preventing Pertussis in the Early Infant: Development and Results of a Prenatal Vaccination Program.

ABSTRACT

Introduction: Cases of Pertussis increase every year with special morbidity and mortality in early infants. The objective was to evaluate results of a program of vaccination of pregnant women launched in our center in 2013. Methods: This is an observational retrospective study. We reviewed all cases of Pertussis disease in our center (2011-2015) and compared clinical data between two groups of age Early infants (<3 months of age) and Other Groups (>3 months). We also compared perinatal events in vaccinated versus non vaccinated pregnant women. Results: During the period 2011-2015, 63 cases (9 in Early Infants; 54 Other Groups) were treated. All cases in Early Infants required hospitalization (100% vs. 3,70%; p<0,05) with more days of hospitalization (10,2 days vs. 0,36 days; p<0,05) and need of oxygen (66,67% vs.3,70%; p<0,05). No differences were seen in response to Azithromycin (87,5% vs. 97,91%; p>0.05) nor in incidence in close relatives (44,44% vs. 27,45%; p>0,05). No differences were observed in Perinatal events in vaccinated vs. non vaccinated in terms of duration of pregnancy (279 days vs. 278 days; p>0,05), weight at birth (3290gr vs. 3220gr; p>0,05), admission at NICU (1,58% vs.1,87%; p>0,05) and Apgar test score <7 at 5 minutes (0,27% vs. 0%; p>0,05). Proportion in early infants affected lowered from 40% in 2011 to 3,85% in 2015. Conclusions: Maternal immunization with Tdap vaccine seems to be a good strategy to reduce incidence of pertussis in the offspring. Additional measures such as vaccinating relatives should be considered.