title: Similar Antibody Levels in 3-Year-Old Children Vaccinated Against Measles, Mumps, and Rubella at the Age of 12 Months or 18 Months.
abstract: Measles-mumps-rubella (MMR) vaccinations have been offered to Finnish children at 14-18 months and 6 years of age. In May 2011, the recommended age for the first vaccine dose was lowered to 12 months because of the European measles epidemic.
  
  
  
  Fingertip capillary blood samples were collected from 3-year-old Finnish children vaccinated once with MMR vaccine at 11-19 months of age. The immunoglobulin G (IgG) antibodies to all 3 MMR antigens were measured with enzyme-linked immunosorbent assay. Neutralizing antibodies and the avidity of antibodies were measured for measles virus.
  
  
  
  From April through October 2013, 187 children were enrolled. Equally high proportions of the samples were seropositive for measles virus, mumps virus, or rubella virus antibodies, and there were no significant differences in the IgG antibody concentrations in children vaccinated at 11-13 months of age, compared with those vaccinated at 17-19 months of age. However, among children vaccinated at 11-13 months of age, boys had lower antibody concentrations than girls. Neutralizing measles virus antibody titers were above the threshold for protective immunity in all 78 samples analyzed. The measles virus antibody avidity indexes were high for all children.
  
  
  
  MMR induces similar antibody responses in 12-month-old children as compared to 18-month-old children, but in boys increasing age appears to improve the antibody responses.
authors.affiliation: Department of Infectious Diseases.
authors.forename: Mia
authors.initials: M
authors.lastname: Kontio
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare.
authors.forename: Arto A
authors.initials: AA
authors.lastname: Palmu
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare.
authors.forename: Ritva K
authors.initials: RK
authors.lastname: Syrjänen
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare.
authors.forename: Mika
authors.initials: M
authors.lastname: Lahdenkari
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare.
authors.forename: Esa
authors.initials: E
authors.lastname: Ruokokoski
authors.affiliation: Department of Infectious Diseases.
authors.forename: Irja
authors.initials: I
authors.lastname: Davidkin
authors.affiliation: Institute of Clinical Medicine, University of Helsinki, Finland.
authors.forename: Outi
authors.initials: O
authors.lastname: Vaarala
authors.affiliation: Department of Health Protection, National Institute for Health and Welfare.
authors.forename: Merit
authors.initials: M
authors.lastname: Melin
mesh_terms: D000367:Age Factors; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005387:Finland; D006801:Humans; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D008297:Male; D008457:Measles / Q000517:prevention & control* / Q000821:virology; D022542:Measles-Mumps-Rubella Vaccine / Q000008:administration & dosage / Q000276:immunology*; D009107:Mumps / Q000517:prevention & control* / Q000821:virology; D012409:Rubella / Q000517:prevention & control* / Q000821:virology; D012737:Sex Factors; D014611:Vaccination
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D022542:Measles-Mumps-Rubella Vaccine
keywords: MMR; antibody; immune response; immunization; measles; mumps; rubella; vaccination schedule; vaccine