according to Stephane Carryn, PhD, of GlaxoSmithKline and associates.
In a phase 3, observer-blind, randomized study published in Vaccine, 1,887 children aged 12-22 months received two doses of the MMR plus varicella (MMRV) vaccine Priorix-Tetra, one dose of the MMR vaccine Priorix with one dose of the varicella vaccine Varilrix delivered separately, or two doses of the MMR vaccine. Blood samples were collected at baseline and at days 42 and 84, then at year 1, 2, 4, 6, 8, and 10.
Antimeasles and antirubella antibodies declined moderately over the 10-year study period, but seropositivity remained high at 10 years, with about 94.0% of children remaining seropositive for antimeasles antibodies and about 96.6% remaining seropositive for antirubella antibodies. Children who received Priorix-Tetra had antimeasles antibody titers twice as high as those who received Priorix throughout the study. In addition, children who received a second dose of MMR vaccine later in life saw only a transient benefit in antimeasles and antirubella titers.
Antimumps antibody titer levels remained stable over the course of the study, and the seropositivity rate was about 90.0% at 10 years. Children who received a second MMR vaccine later in life saw a boosting effect in seropositivity and antimumps antibody titer levels.
“The responses obtained after receipt of one or two doses of MMR-containing vaccines remain well above the seropositivity thresholds up to 10 years post vaccination, regardless of the vaccine given and the schedule used,” the investigators concluded.
The study was funded and supported by GlaxoSmithKline. The study authors reported being employed by GlaxoSmithKline; two also reported owning shares in the company.
SOURCE: Carryn S et al. Vaccine. 2019 Jul 22. doi: 10.1016/j.vaccine.2019.07.049.