A new measles mumps rubella (MMR) vaccine: a randomized comparative trial for assessing the reactogenicity and immunogenicity of three consecutive production lots and comparison with a widely used MMR vaccine in measles primed children.

OBJECTIVES: A multicenter, single-blind, randomized, controlled clinical study was conducted in healthy 15-18-month-old children in order to assess the immunogenicity and reactogenicity of three consecutive lots of a new measles- mumps-rubella (MMR) vaccine, GSK MMR.

DESIGN: A total of 500 enrolled subjects were randomized into four groups to receive either a single dose of one of the three lots of GSK MMR (three groups--125 subjects in each group) or Merck MMR vaccine (125 subjects). Once clinical consistency had been demonstrated, the data were pooled and compared with the widely used Merck vaccine. Solicited local and general symptoms were recorded using diary cards, and antibody levels were determined using ELISA assays.

RESULTS: No differences in the incidence of local and general symptoms or seroconversion rates were seen in the groups receiving different lots of GSK MMR. Compared with Merck MMR, there was a significantly lower incidence of local pain (P<0.001) and swelling (P=0.038) in infants receiving the GSK MMR vaccine. The incidences of all other solicited local and general symptoms were comparable between the two groups. No signs of suspected meningitis were reported. No serious adverse events were reported by the investigator to be related to vaccination. Equivalent seroconversion rates and postvaccination GMTs were observed in the groups receiving the two MMR vaccines. In conclusion, the new GSK MMR vaccine administered in measles-primed children demonstrated satisfactory immunogenicity and safety profiles as good as the Merck MMR vaccine.