Safety and immunogenicity of early vaccination with two doses of tetravalent measles-mumps-rubella-varicella (MMRV) vaccine in healthy children from 9 months of age.

BACKGROUND: This open, randomized, controlled study [208136/018] assessed the safety and immunogenicity of early vaccination with an experimental tetravalent measles-mumps-rubella-varicella (MMRV) vaccine (GlaxoSmithKline Biologicals) compared to concomitant administration of separate licensed MMR (Priorix) and varicella (Varilrix) vaccines (MMR+V).

METHODS: Vaccines were administered as a two-dose course in healthy children at 9 and 12 months of age (N = 153 in the MMRV group and N = 146 in the MMR+V group).

RESULTS: The incidence of fever of any intensity (axillary temperature > or = 37.5 degrees C) during the 15 days of follow-up post-dose 1 was higher in the MMRV group than in the MMR+V group (48.3% vs 25.7%, respectively) but was low in both groups post-dose 2 (20.3% and 22.1%, respectively). The incidence of fever > 39.0 degrees C and the incidence of solicited local symptoms (pain, redness, swelling) were low ( < or = 5.3% and < or = 13.7%, respectively) in the two groups after each vaccine dose. Seroconversion rates were similar in the two groups for all vaccine antigens after each vaccine dose and were > or = 99.2% for each antigen post-dose 2. Anti-measles GMT was higher in the MMRV group than in the MMR+V group after the first vaccine dose. After the second dose, slight to moderate increases in measles, mumps and rubella antibody titers and a substantial increase in varicella antibody titer were seen in both groups, leading to higher GMTs in the MMRV group compared with the MMR+V group for measles, mumps and varicella. Anti-rubella antibody GMTs were similar in the two groups post-dose 2.

CONCLUSION: Early vaccination with two doses of this experimental MMRV vaccine at 9 and 12 months of age was well-tolerated and at least as immunogenic as two doses of separate licensed MMR and varicella vaccines.