Vaccine-derived rotavirus strains in infants in England
Gower CM., Dunning J., Nawaz S., Allen D., Ramsay ME., Ladhani S.
ObjectiveTo describe infants with acute gastroenteritis symptoms in primary and secondary care who have the Rotarix vaccine-derived G1P rotavirus strain identified in their stools.DesignThis is a prospective national surveillance conducted by Public Health England (PHE). Rotavirus-positive samples from vaccine-eligible children are routinely submitted to PHE for confirmation, and general practitioners are requested to complete a surveillance questionnaire for all cases. The modified Vesikari Score was used to assess severity of gastroenteritis.SettingEngland, July 2013–September 2016.Results2637 rotavirus strains were genotyped and 215 (8%) identified as the Rotarix vaccine-derived G1P strain. There were no Rotarix vaccine-derived G1P strains detected in unimmunised infants. Rotarix vaccine-derived G1P strains clustered around the time of rotavirus vaccination and were responsible for 82% (107 of 130) of rotavirus-positive samples in 2-month-old infants and 68% (36 of 53) in 3-month-old infants. However, 13 samples were obtained more than 7 weeks after the last vaccination date; 10 of these specimens were from six children who were subsequently diagnosed with severe combined immunodeficiency (SCID). Diarrhoea was the single most common presenting symptom (83.0%) in infants with Rotarix vaccine-derived G1P strains, who were less likely to present with fever, vomiting, dehydration or severe gastroenteritis than infants with wild-type rotavirus infection.ConclusionsRotavirus identified in stools of infants around the time of their routine immunisations is most likely the Rotarix vaccine-derived G1P strain. Infants with undiagnosed SCID at the time of rotavirus immunisation may experience prolonged gastroenteritis symptoms. Most infants with vaccine strains in their stools more than 7 weeks after immunisation had SCID.