Effectiveness of the Lanzhou lamb rotavirus vaccine against gastroenteritis among children.

The Lanzhou lamb rotavirus (LLR) vaccine has been in use in China since 2000. This study evaluated this vaccine's effectiveness using a case-control design in Guangzhou. In the study area, there were 3130 laboratory-confirmed rotavirus gastroenteritis cases in children between 2 and 35 months old from 2009 to 2011. A total of 3607 controls were also enrolled in this study. Of the subjects, 970 (14.4%) had received 1 dose of the LLR vaccine. Because of the low vaccination rate, we only obtained an effectiveness of 44.3% (95% CI, 28.4-56.7%) for children 9-11 months old, 52.8% (40.8-62.3%) for children 12-17 months old, and 51.8% (11.6-73.8%) for children 18-35 months old for one dose. This post-marketing study found that one dose of the LLR vaccine confers partial protection when given to children between 9 and 35 months old. Therefore, earlier immunization and the administration of the full immunization regimen should be encouraged.