The coefficient is the regression correlation coefficient, and the adjusted R2 is the proportion of between-study variance explained. Metaregression between immunogenicity and logRR against rotavirus gastroenteritis (RVGE) for RV1 and RV5 (A), RVGE for RV1 (B), severe RVGE for RV1 and RV5 (C), severe RVGE for RV1 (D), and severe RVGE for RV5 (E). RV1 indicates monovalent rotavirus vaccine; RV5, pentavalent rotavirus vaccine.