ABSTRACT
In this double-blind, randomized single-dose study, 194 healthy Filipino children aged 12-24 months were randomized into three groups (1:1:1) to receive one of the three lots of live-attenuated measles-mumps-rubella (MMR) vaccine to assess lot-to-lot consistency in safety and immunogenicity. Adverse events were recorded during 43-day post-vaccination follow-up period. Antibody levels were measured using ELISA pre-vaccination and on Day-60. No statistically significant differences were observed across groups for overall incidences of local and general symptoms (p>0.05) or immune response rates against the three antigens (p=0.835, 0.458 and 0.222 for anti-measles, anti-mumps and anti-rubella, respectively). The three lots demonstrated consistency in their reactogenicity and immunogenicity profile.