title: Supplemental measles vaccine antibody response among HIV-infected and -uninfected children in Malawi after 1- and 2-dose primary measles vaccination schedules.
abstract: BACKGROUND
  The long-term antibody response to measles vaccine (MV) administered at age 6 months with or without subsequent doses is not well documented.
  
  
  METHODS
  Measles serum antibody responses were evaluated after a supplemental dose of measles vaccine (sMV) administered at a median age of 20 months among Malawian children who had previously received 2 doses of measles vaccine (MV) at ages 6 and 9 months (HIV-infected and random sample of HIV-uninfected) or 1 dose at age 9 months (random sample of HIV-uninfected). We compared measles antibody seropositivity between groups by enzyme linked immunoassay and seroprotection by plaque reduction neutralization geometric mean concentrations.
  
  
  RESULTS
  Of 1756 children enrolled, 887 (50.5%) received a sMV dose following MV at 9 months of age and had specimens available after sMV receipt, including 401 HIV-uninfected children who received one MV dose at 9 months, 464 HIV-uninfected and 22 HIV-infected children who received two doses of MV at ages 6 and 9 months. Among HIV-uninfected children, protective levels of antibody were found post sMV in 90-99% through ages 24-36 months and were not affected by MV schedule. Geometric mean concentration levels of measles antibody were significantly increased post-sMV among those HIV-uninfected children previously non-responsive to vaccination. Among HIV-infected children, the proportion seroprotected increased initially but by 9 months post-sMV was no higher than pre-sMV.
  
  
  CONCLUSIONS
  Our findings support early 2-dose MV to provide measles immunity for young infants without risk of interference with antibody responses to subsequent MV doses administered as part of SIAs.
authors.affiliation: Centers for Disease Control and Prevention (CDC), Atlanta, GA USA. Electronic address: afowlkes@cdc.gov.
authors.forename: Ashley L
authors.initials: AL
authors.lastname: Fowlkes
authors.affiliation: College of Medicine, University of Malawi, Blantyre, Malawi.
authors.forename: Desiree
authors.initials: D
authors.lastname: Witte
authors.affiliation: Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD, USA.
authors.forename: Judy
authors.initials: J
authors.lastname: Beeler
authors.affiliation: Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD, USA.
authors.forename: Susette A
authors.initials: SA
authors.lastname: Audet
authors.affiliation: College of Medicine, University of Malawi, Blantyre, Malawi.
authors.forename: Robin
authors.initials: R
authors.lastname: Broadhead
authors.affiliation: Centers for Disease Control and Prevention (CDC), Atlanta, GA USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Bellini
authors.affiliation: London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Felicity
authors.initials: F
authors.lastname: Cutts
authors.affiliation: Centers for Disease Control and Prevention (CDC), Atlanta, GA USA.
authors.forename: Rita F
authors.initials: RF
authors.lastname: Helfand
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D005260:Female; D015658:HIV Infections; D006801:Humans; D056724:Immunity, Humoral; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007223:Infant; D008295:Malawi; D008297:Male; D008457:Measles / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000914:Antibodies, Viral; D008458:Measles Vaccine
keywords: Antibody response; HIV; Measles vaccine; Neutralizing antibody; Supplementary immunization activity