title: Immunogenicity and safety of inactivated monovalent 2009 H1N1 influenza A vaccine in immunocompromised children and young adults.
abstract: BACKGROUND
  Influenza vaccination is recommended for immunocompromised patients.
  
  
  METHODS
  Children (6 months to 21 years) with cancer, HIV infection, or sickle cell disease (SCD) received 1 or 2 doses of pandemic 2009 H1N1 monovalent influenza vaccine (H1N1 MIV). Safety and tolerability, hemagglutination inhibition (HI) and microneutralization (MN) antibody titers were measured against 2009 H1N1 influenza A virus after each dose. Seroprotection (SP) and seroconversion (SC) rates were determined.
  
  
  RESULTS
  103 participants were enrolled and 99 were evaluable (39 with HIV, 37 with cancer and 23 with SCD). Mean age (±SD) was 7.9 (±5.4) years for cancer participants, 18.0 (±3.5) for HIV, and 13.3 (±4.2) for SCD. 54% were males; 65% black; and 96% had received seasonal influenza vaccine. HIV-infected participants had a median CD4 count of 625 cells/mm(3) (range, 140-1260). 46% had an undetectable HIV viral load and 41% were perinatally infected. No participant had vaccine-related serious adverse events. None developed influenza A proven illness during the 6 months after the vaccine. Local injection reactions were reported in 29% and systemic reactions in 42% after the first dose of vaccine. SC and SP were achieved after the last dose in 48% and 52%, respectively, of participants with leukemia or lymphoma, 50% and 75% of participants with solid tumors, 63% and 92% of HIV-infected participants, and 74% and 100% of participants with SCD.
  
  
  CONCLUSIONS
  H1N1 MIV was safe and well tolerated. H1N1 MIV resulted in an adequate immune response in children with SCD. It was only modestly immunogenic in cancer or HIV participants.
authors.affiliation: Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105-3678, United States. Hana.Hakim@stjude.org
authors.forename: Hana
authors.initials: H
authors.lastname: Hakim
authors.forename: Kim J
authors.initials: KJ
authors.lastname: Allison
authors.forename: Lee-Ann
authors.initials: LA
authors.lastname: Van De Velde
authors.forename: Yimei
authors.initials: Y
authors.lastname: Li
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Flynn
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: McCullers
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D015658:HIV Infections / Q000276:immunology; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D009369:Neoplasms / Q000276:immunology; D009500:Neutralization Tests; D011446:Prospective Studies; D014611:Vaccination / Q000379:methods*; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines