title: Immunogenicity of Licensed Influenza A (H1N1) 2009 Monovalent Vaccines in HIV-Infected Children and Youth.
abstract: BACKGROUND
  With the emergence of pandemic influenza A (pH1N1) in 2009, children and youth infected with human immunodeficiency virus (HIV) were vulnerable because of immunologic impairment and the greater virulence of this infection in young persons.
  
  
  METHODS
  A multicenter study of the immunogenicity of 3 licensed influenza A (H1N1) monovalent vaccines (1 live attenuated and 2 inactivated) was conducted in children and youth with perinatal HIV infection, most of whom were receiving ≥3 antiretroviral drugs, had CD4% ≥15, and plasma HIV RNA levels <400 copies/mL. Serum hemagglutinin inhibition assay (HAI) antibody levels were measured and correlated with baseline demographic and clinical variables.
  
  
  RESULTS
  One hundred forty-nine subjects were enrolled at 26 sites in the United States and Puerto Rico. Over 40% had baseline HAI titers ≥40. For subjects aged 6 months to <10 years, 79% and 68%, respectively, achieved a ≥40- and ≥4-fold rise in HAI titers after the second dose of vaccine. Three weeks after a single immunization with an inactivated vaccine, similar immunogenicity results were achieved in youth aged 10-24 years. With multivariable analysis, only Hispanic ethnicity and CD4% ≥15 were associated with achieving both HAI titer ≥40- and ≥4-fold rise in titer.
  
  
  CONCLUSIONS
  Although licensed pH1N1 vaccines produced HAI titers that were considered to be protective in the majority of HIV-infected children and youth, the proportion with titers ≥40- and ≥4-fold rise in titer was lower than expected for children without HIV infection. Vaccine immunogenicity was lower in HIV-infected children and youth with evidence of immune suppression.
authors.affiliation: University of Alabama at Birmingham rpass@peds.uab.edu.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Pass
authors.affiliation: SUNY Health Science Center at Stony Brook, New York.
authors.forename: Sharon
authors.initials: S
authors.lastname: Nachman
authors.affiliation: St Jude's Children's Research Hospital, Memphis, Tennessee.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Flynn
authors.affiliation: Statistical and Data Analysis Center, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Petronella
authors.initials: P
authors.lastname: Muresan
authors.affiliation: Statistical and Data Analysis Center, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Terence
authors.initials: T
authors.lastname: Fenton
authors.affiliation: Duke University Medical Center, Durham, North Carolina.
authors.forename: Coleen K
authors.initials: CK
authors.lastname: Cunningham
authors.affiliation: NYU Medical Center, New York, New York.
authors.forename: William
authors.initials: W
authors.lastname: Borkowsky
authors.affiliation: Rush Medical Center, Chicago, Illinois.
authors.forename: James B
authors.initials: JB
authors.lastname: McAuley
authors.affiliation: University of California San Diego, La Jolla Rady Children's Hospital, San Diego, California.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Spector
authors.affiliation: Social and Scientific Systems, Silver Spring.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Petzold
authors.affiliation: Social and Scientific Systems, Silver Spring.
authors.forename: Wende
authors.initials: W
authors.lastname: Levy
authors.affiliation: Pediatric Adolescent and Maternal AIDS Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda.
authors.forename: George K
authors.initials: GK
authors.lastname: Siberry
authors.affiliation: Division of AIDS, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland.
authors.forename: Ed
authors.initials: E
authors.lastname: Handelsman
authors.affiliation: St Jude's Children's Research Hospital, Memphis, Tennessee.
authors.forename: L Jill
authors.initials: LJ
authors.lastname: Utech
authors.affiliation: University of Colorado Denver, Aurora.
authors.forename: Adriana
authors.initials: A
authors.lastname: Weinberg