Immunogenicity and safety of a measles-mumps-rubella-varicella vaccine following a 4-week or a 12-month interval between two doses.

BACKGROUND: The MMRV combination vaccine, Priorix-Tetra™, is currently licensed in several European countries using a two-dose schedule in infants aged ≥9 months, with a preferred 6-week to 3-month interval between doses. This study was undertaken to generate safety and immunogenicity data for two doses of MMRV vaccine administered according to dose schedules using the shortest permitted interval of 4 weeks versus a longer interval of 12 months, which would allow flexible adaptation to local immunization calendars. METHODS: Healthy children aged 11-13 months were randomized (1:1:1) to receive 2 doses of either: MMRV vaccine with a 4-week interval between doses (MMRV-4W group, N=188), MMRV vaccine with a 12-month interval between doses (MMRV-12M group, N=184), or MMR vaccine with a 4-week interval between doses (MMR group, N=187). Blood samples were taken prior to, and 4-6 weeks after each vaccination. RESULTS: Post-Dose 2, both MMRV groups exhibited an adequate immunogenic response for all components; however the MMRV-12M group showed significantly greater geometric mean titers for mumps, rubella and varicella. Two varicella breakthrough cases occurred within the 12-month interval between doses in the MMRV-12M group. Local and general reactogenicity results were similar for all groups except for the MMRV-4W group, which had a greater incidence of fever during Days 0-14 post-Dose 1. CONCLUSIONS: Two doses of MMRV vaccine administered in the second year of life elicited adequate immunogenicity and were well-tolerated whether administered with a dose interval of 4 weeks or 12 months.

Immunogenicity and safety of measles-mumps-rubella-varicella (MMRV) vaccine followed by one dose of varicella vaccine in children aged 15 months-2 years or 2-6 years primed with measles-mumps-rubella (MMR) vaccine.

In this open, randomized, comparative study (105908/NCT00353288), 458 age-stratified children (15 months-2 years and 2-6 years) previously primed with MMR received one dose of either a combined MMRV vaccine (Priorix-Tetra, MMRV group) or concomitant MMR and varicella vaccines (Priorix and Varilrix, MMR+V group), followed 42-56 days later by another dose of varicella vaccine (Varilrix) in both groups. Post-vaccination measles, mumps and rubella seropositivity rates and antibody geometric mean titers (GMTs) were high (99.5% for anti-measles and 100% for anti-mumps and anti-rubella) in both vaccine groups. In the two age strata, varicella seroconversion rates were, post-dose 1: > or =97.6% (MMRV), > or =96.6% (MMR+V) and, post-dose 2: 100% in both groups. Post-dose 2, anti-varicella GMTs increased respectively 14.1- and 12.6-fold (MMRV), and 9.8- and 13.1-fold (MMR+V). Both vaccine regimens were well-tolerated. Post-dose 1, the incidence of any solicited local symptom during the 4-days follow-up was < or =28.2% (MMRV) and < or =19.8% (MMR+V) and the incidence of fever >39.5 degrees C (rectal temperature) within 15 days was < or =2.8% (MMRV) and < or =2.6% (MMR+V). This MMRV vaccine appears an immunogenic and safe substitute for a second dose of MMR vaccine in young children. The increase in anti-varicella antibodies observed after a second dose of varicella vaccine supports a two-dose schedule for varicella-containing vaccine.