Rotavirus vaccine effectiveness against all cause medically attended acute gastroenteritis and hospitalizations in children in England

Date of ISAC Approval: 
Lay Summary: 
Rotavirus is the main cause of severe diarrhoea in children. Rotavirus vaccines are available and are recommended to be introduced in national vaccination schedules by the World Health Organization. The United Kingdom started rotavirus vaccination of infants in July 2013. Recent studies have already shown an impact in the reduction of all diarrhoea episodes in children in the first year after vaccine introduction. With this study, we aim to estimate the effectiveness of rotavirus vaccination in reducing the number of diarrhoea episodes in children as well as among household members, both requiring general practitioner care only or hospitalization. In addition, we will estimate the overall impact of the vaccination programme on the number of diarrhea episodes consulting a general practitioner or requiring hospitalization for all ages. In order to achieve these objectives, we will use general practitioner and hospital medical records contained in the Clinical Practice Research Datalink (CPRD) and Hospital Episodes Statistics Admitted Patient Care (HES APC) databases. The study will include all records for patients registered in or after January 2010.
Technical Summary: 
Rotavirus is the main cause of severe acute gastroenteritis (AGE) in children. Rotavirus vaccines have been available since 2006, and their introduction in the National Immunization Programme (NIP) was recommended by WHO the same year. The UK introduced rotavirus vaccination in July 2013, and recent studies have already shown an impact in the reduction of all cause acute gastroenteritis and rotavirus disease in children. However, these studies used an ecological study design, but without attempting to measure directly rotavirus vaccine effectiveness. With this study, we aim to estimate both the direct and indirect effects of rotavirus vaccination against all cause and cause-specific medically-attended acute gastroenteritis (MAAGE) in England using the CPRD and HES APC databases. This will be a retrospective observational study using a cohort design including all subjects registered in CPRD in or after January 2010. Episode rate ratios comparing the vaccinated to the unvaccinated will be calculated to estimate vaccine effectiveness (VE). VE will be calculated as VE=1-RR for RR<1 and VE=1/RR-1 for RR>1 and expressed as percentage. Episode rate ratios comparing the population before and after vaccination introduction will be calculated to estimate impact. Confidence intervals will be based on the exact binomial Clopper-Pearson method.
Health Outcomes to be Measured: 
- Incidence of medically-attended acute gastroenteritis (GP level and hospitalizations) - Rotavirus vaccination coverage - Incidence of aetiology-specific medically attended acute gastroenteritis - Incidence of intussusception

Margarita Riera-Montes - Chief Investigator - P95
Dr Germano Ferreira - Collaborator - Not from an Organisation
Ms Kaatje (Kaat) Bollaerts - Collaborator - P95
Margarita Riera-Montes - Corresponding Applicant - P95
Dr Thomas Verstraeten - Collaborator - P95
Mr Tom Cattaert - Collaborator - P95
Tom De Smedt - Collaborator - P95

HES Admitted;HES Admitted;Patient IMD;Patient IMD