A Matched Case-Control Study Measuring the Effectiveness of the Rotavirus Vaccines to Prevent Gastroenteritis Hospitalizations

Francisco Gimenez-Sanchez, Elena Cobos-Carrascosa, Miguel Sanchez-Forte, Yolanda Gonzalez-Jimenez, Ernestina Azor-Martine and Pablo Garrido- Fernandez

Rotavirus has been identified as an important cause of diarrhea hospitalizations. Two oral live rotavirus vaccines have been licensed in Europe since 2006 and have been available in the Spanish market since then. The main objective of this study was to estimate the effectiveness of the rotavirus vaccination in the prevention of admissions caused by rotavirus infections using a matched case-control study in a hospital setting.

Patients and methods: Prospective, hospital based, matched case-control study including patients between aged between 2 months and 5 years, hospitalized during 2008-2010 with a diagnosis of Rotavirus Acute Gastroenteritis (RV+AGE) matched against two patients diagnosed as Rotavirus negative Acute Gastroenteritis (Control group A) and five patients hospitalized with non-gastrointestinal conditions (Control group B) (i.e. in the ratio 1:2:5).

Results: 466 patients were included: 57 cases of RV+AGE, 104 patients in Control group A and 305 in Control group B. No differences were found among the 3 groups when comparing demographic data. Vaccine effectiveness was estimated as 86% (95% CI 59-95) compared to group A and 88% (95% CI 68-95) compared to group B. Prior rotavirus vaccination was more frequent in mild cases than in those with moderate-severe symptoms and the length of admission was shorter in vaccine recipients (1.7 ± 0.8 days) compared to those non-vaccinated (3.2 ± 1.4 days) (p<0.001; 95% CI: 1.3-1.7).

Conclusions: Our study found the rotavirus vaccines to be highly effective in preventing rotavirus-related hospitalizations and to reduce the severity of the rotavirus disease.