137 Bradycardia/Desaturation/Apnea After Vaccination in the Very Low Birth Weight Newborns. A Prospective Study

Abstract

Severe adverse reactions, i.e. apnea, bradycardia and desaturation, have been reported after DTP-Hib immunization in very preterm infants. The aim of this study was to evaluate the safety of a hexavalent vaccine (DTPa+IPV+Hib+HBV). All newborns < 30 week GA or < 1250g BW were prospectively enrolled to have their first dose of vaccine at 6–8 weeks of life, while being in our NICU. They were on continuous monitoring for 3 days before and 3 days after the vaccination, and all episodes of bradycardia/desaturation/apnea and related interventions were recorded. Between November 2003 and March 2005, 40 newborns were studied. BW was 924g (range 475-1445g) and GA was 27.5 wks (range 24 - 30 wks). Four severe adverse events were recorded. In detail: 1 case of apnea the day following the vaccination resolved with manual ventilation. A similar episode of apnea was recorded also before the vaccination. 1 case of desaturation the day following the vaccination concomitant with the meal and spontaneously resolved. An episode of desaturation in concomitance with the meal was recorded during the preceding monitoring. 1 case of desaturation the day preceding the administration of the vaccine. After the vaccination, two more episodes of spontaneously resolved desaturation were recorded. The examinations revealed a CMV infection. 1 case of bradycardia and desaturation the first day after the vaccination that required manual ventilation and an increased oxygen flow for some days. The examinations revealed a Rotavirus infection. In previous studies every new bradycardia/desaturation/apnea event or a 50% increase of these events after the vaccine administration was considered related to it. According to these criteria, two out of 40 infants (5%) had severe adverse reactions related to the vaccine, but the concomitant infections from CMV and Rotavirus respectively may have played a major role.