title: Outbreak of measles among persons with prior evidence of immunity, New York City, 2011.
abstract: BACKGROUND
  Measles was eliminated in the United States through high vaccination coverage and a public health system able to rapidly respond to measles. Measles may occur among vaccinated individuals, but secondary transmission from such individuals has not been documented.
  
  
  METHODS
  Suspected patients and contacts exposed during a measles outbreak in New York City in 2011 were investigated. Medical histories and immunization records were obtained. Cases were confirmed by detection of measles-specific immunoglobulin M and/or RNA. Tests for measles immunoglobulin G (IgG), IgG avidity, measurement of measles neutralizing antibody titers, and genotyping were performed to characterize the cases.
  
  
  RESULTS
  The index patient had 2 doses of measles-containing vaccine; of 88 contacts, 4 secondary patients were confirmed who had either 2 doses of measles-containing vaccine or a past positive measles IgG antibody. All patients had laboratory confirmation of measles infection, clinical symptoms consistent with measles, and high-avidity IgG antibody characteristic of a secondary immune response. Neutralizing antibody titers of secondary patients reached >80 000 mIU/mL 3-4 days after rash onset and that of the index was <500 mIU/mL 9 days after rash onset. No additional cases of measles occurred among 231 contacts of secondary patients.
  
  
  CONCLUSIONS
  This is the first report of measles transmission from a twice-vaccinated individual with documented secondary vaccine failure. The clinical presentation and laboratory data of the index patient were typical of measles in a naive individual. Secondary patients had robust anamnestic antibody responses. No tertiary cases occurred despite numerous contacts. This outbreak underscores the need for thorough epidemiologic and laboratory investigation of suspected cases of measles regardless of vaccination status.
authors.affiliation: Bureau of Immunization, New York City Department of Health and Mental Hygiene, New York.
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Rosen
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Rota
authors.forename: Carole J
authors.initials: CJ
authors.lastname: Hickman
authors.forename: Sun B
authors.initials: SB
authors.lastname: Sowers
authors.forename: Sara
authors.initials: S
authors.lastname: Mercader
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rota
authors.forename: William J
authors.initials: WJ
authors.lastname: Bellini
authors.forename: Ada J
authors.initials: AJ
authors.lastname: Huang
authors.forename: Margaret K
authors.initials: MK
authors.lastname: Doll
authors.forename: Jane R
authors.initials: JR
authors.lastname: Zucker
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Zimmerman
mesh_terms: D000328:Adult; D000368:Aged; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D000915:Antibody Affinity; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008457:Measles / Q000453:epidemiology / Q000276:immunology / Q000635:transmission*; D008458:Measles Vaccine / Q000008:administration & dosage / Q000627:therapeutic use; D008875:Middle Aged; D009519:New York City; D014611:Vaccination
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008458:Measles Vaccine
keywords: immunity; measles; outbreak; vaccine failure; waning immunity