Rotavirus shedding in premature infants following first immunization.

OBJECTIVE: There is limited data regarding rotavirus vaccine shedding in premature infants. We describe the natural history of rotavirus shedding in premature infants in the 2-week period following first immunization with RotaTeq(®), the pentavalent rotavirus vaccine (RV5), and the risk for symptomatic transmission to household contacts (HHC). PATIENTS AND METHODS: A prospective pilot study of 15 premature infants of gestational ages 26-34 weeks immunized with RV5 between 6 and 14 weeks chronological age on discharge from the NICU was conducted. Stool samples collected in the following 2 weeks and analyzed for rotavirus antigen by enzyme immunoassay (EIA), cell culture, and RT-PCR. Solicited adverse events were collected on study subjects and any symptoms of fever, vomiting and diarrhea in HHC.
RESULTS: Rotavirus antigen shedding after immunization was detected, with positive rotavirus EIA results in 53.3% of premature infants and in 22.1% of 86 stool samples collected. Shedding rates by RT-PCR were higher with 86.7% of infants and 76.7% of samples being positive. Only 42% of EIA positive samples were positive by cell culture (8/86 total samples, 9.3%). None of 53 HHC reported symptoms of rotavirus infection during the 4 weeks following immunization of the infants.
CONCLUSIONS: The findings of this study demonstrate that premature infants have positive stools by EIA, viral culture, and RT-PCR at varying time points during 2 weeks following first-dose immunization with RV5. RT-PCR shedding rates need to be clinically evaluated in the context of virus quantification by cell culture, which was low. No symptomatic transmission to HHC was detected in this study, supporting low transmissibility of vaccine virus shed by these infants born prematurely.