title: Persistence of rubella antibodies after 2 doses of measles-mumps-rubella vaccine.
abstract: BACKGROUND
  Since 1990, most schoolchildren in the United States have received a second dose of measles-mumps-rubella vaccine (MMR2) at kindergarten entry. Elimination of endemic rubella virus circulation in the United States was declared in 2004. The objective of the current study was to evaluate the short- and long-term rubella immunogenicity of MMR2.
  
  
  METHODS
  At enrollment in 1994-1995, children (n = 307) in a rural Wisconsin health maintenance organization received MMR2 at age 4-6 years. A comparison group of older children (n = 306) was vaccinated at age 9-11 years. Serum specimens were collected during a 12-year period. Rubella antibody levels were evaluated by plaque-reduction neutralization (lowest detectable titer, 1:10).
  
  
  RESULTS
  Before administration of MMR2 in the kindergarten group, 9% of subjects were seronegative, 60% had the lowest detectable titer, and the geometric mean titer (GMT) was 1:13. One month after administration of MMR2, 1% were seronegative, 6% had the lowest detectable titer, and the GMT was 1:42. Four-fold boosts occurred in 62% of subjects, but only 0.3% were immunoglobulin M positive. Twelve years after MMR2 administration, 10% were seronegative, 43% had the lowest detectable titer, and the GMT was 1:17. The middle-school group showed similar patterns.
  
  
  CONCLUSIONS
  Rubella antibody response to MMR2 was vigorous, but titers decreased to pre-MMR2 levels after 12 years. Because rubella is a highly epidemic disease, vigilance will be required to assure continued elimination.
authors: Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, 16 Clifton Road, Atlanta, GA 30333, USA. clebaron@cdc.gov
authors: Charles W
authors: CW
authors: LeBaron
authors: Bagher
authors: B
authors: Forghani
authors: Lukas
authors: L
authors: Matter
authors: Susan E
authors: SE
authors: Reef
authors: Carol
authors: C
authors: Beck
authors: Daoling
authors: D
authors: Bi
authors: Cynthia
authors: C
authors: Cossen
authors: Bradley J
authors: BJ
authors: Sullivan
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D022542:Measles-Mumps-Rubella Vaccine / Q000276:immunology*; D012307:Risk Factors; D014922:Wisconsin
chemical_list: D000914:Antibodies, Viral; D022542:Measles-Mumps-Rubella Vaccine; C040901:rubella antibodies