Rotavirus vaccine-derived shedding and viral reassortants

Two live, attenuated rotavirus vaccines, RotaTeq^® (Merck) and Rotarix^® (GlaxoSmithKline), have been used in Australia since July 2007 to prevent severe rotavirus gastroenteritis in children. Using active postvaccination monitoring, passive surveillance and state-of-the-art laboratory techniques, Donato et al. report that RotaTeq rotavirus vaccine and vaccine-derived strains were detected actively in stool samples from 13 out of 61 (21.3%) infants having diarrhea within 2 weeks of rotavirus vaccination, and among three out of 460 (0.7%) cases with acute gastroenteritis captured via the Australian Rotavirus Surveillance Program. Six (37.5%) of these 16 vaccine-derived viral specimens were associated with a G1P[8] strain thought to be the result of genetic reassortment between two component RotaTeq strains. Although nearly half of these reassortant-associated cases had underlying medical conditions, such as severe combined immunodeficiency disorder, further study is needed to understand the relationship between shedding, viral reassortants and underlying medical conditions.

Source: Expert Review of Vaccines,