RESUMEN
The reactogenicity and immunogenicity of three combined measles, mumps and rubella (MMR) vaccines and one administered with a varicella vaccine was studied in infants. The vaccines were Priorix (designated MeMuRu, Group 1), M-M-R II (Group 2), Triviraten (Group 3) and Priorix + a varicella vaccine, Varilrix (Group 4). Fever was greater in Group 2 (61.3%) compared to Group 1 (48.5%; p = 0.033) or Group 3 (37.1%; p = 0.009). Rash with fever was reported in Group 2 (4.8%) and Group 4 (3.3%), but not for Group 1. Anti-measles, -mumps and -rubella seroconversion was similar for Group 1 (96.1%, 96.1% and 100%, respectively), Group 4 (98% for all three), and Group 2 (91.5%, 93.6% and 97.9%) 60 days post-vaccination. GMTs for measles (3,053.7-3,412.2 mIU/ml), mumps (1,001.5-1,158.8 U/ml) and rubella (68.7-89.1 IU/ml) were similar for Groups 1, 2 and 4 at Day 60. Antibody persistence was noted 2 years post-vaccination. The MeMuRu + varicella combination showed no clinically relevant increase in reactogenicity and should facilitate introduction of a varicella vaccine into national immunization schedules.