Rotavirus Shedding in Feces of Gnotobiotic Calves Orally Inoculated with a Commercial Rotavirus-Coronavirus Vaccine

Abstract

The purpose of this study was to monitor by negative stain electron microscopy the shedding of rotavirus in the feces of gnotobiotic calves orally inoculated with a commercial modified live bovine rotavirus-bovine coronavirus vaccine. Negative stain electron microscopic examination detected vaccine rotavirus in only 1 of 41 daily fecal specimens collected from 3 gnotobiotic calves during the 2 weeks following oral inoculation with a US Department of Agriculture-licensed modified live bovine rotavirus-bovine coronavirus vaccine. In contrast, rotavirus was demonstrable by the same negative stain electron microscopic examination procedure in 17 of 19 fecal specimens collected from diarrheic gnotobiotic or colostrum-deprived calves during the first 8 days after inoculation with virulent bovine rotavirus field strains. Rotavirus was also detected by this procedure in 4 enzyme-linked immunosorbent assay positive fecal specimens collected from naturally-infected diarrheic dairy calves. These results suggest that fecal shedding of vaccine rotavirus demonstrable by electron microscopic examination is uncommon following oral inoculation of calves with the bovine rotavirus-bovine coronavirus vaccine.