No announcement yet.

Emerg Infect Dis. Reproducibility of Serologic Assays for Influenza Virus A (H5N1).

  • Filter
  • Time
  • Show
Clear All
new posts

  • Emerg Infect Dis. Reproducibility of Serologic Assays for Influenza Virus A (H5N1).

    Abstract. Reproducibility of Serologic Assays for Influenza Virus A (H5N1).

    DOI: 10.3201/eid1508.081754

    Suggested citation for this article: Stephenson I, Heath A, Major D, Newman RW, Hoschler K, Junzi W, et al. Reproducibility of serologic assays for influenza virus A (H5N1). Emerg Infect Dis. 2009 Aug; [Epub ahead of print]

    Reproducibility of Serologic Assays for Influenza Virus A (H5N1)

    Iain Stephenson, Alan Heath, Diane Major, Robert W. Newman, Katja Hoschler, Wang Junzi, Jacqueline M. Katz, Jerry P. Weir, Maria C. Zambon, and John M. Wood

    Author affiliations: University of Leicester, Leicester, UK (I. Stephenson); National Institute for Biological Standards and Controls, Potters Bar, UK (A. Heath, D. Major, R.W. Newman, J.M. Wood); Health Protection Agency, Colindale, UK (K. Hoschler, M.C. Zambon); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (J.M. Katz); Food and Drug Administration, Rockville, Maryland, USA (J. Weir); and National Institute for the Control of Pharmaceutical and Biological Products, Beijing, People?s Republic of China (W. Junzhi)

    Hemagglutination-inhibition (HI) and neutralization are used to evaluate vaccines against influenza virus A (H5N1); however, poor standardization leads to interlaboratory variation of results.

    A candidate antibody standard (07/150) was prepared from pooled plasma of persons given clade 1 A/Vietnam/1194/2004 vaccine.

    To test human and sheep antiserum, 15 laboratories used HI and neutralization and reassortant A/Vietnam/1194/2004, A/turkey/Turkey/1/2005 (clade 2.2), and A/Anhui/1/2005 (clade 2.3.4) viruses.

    Interlaboratory variation was observed for both assays, but when titers were expressed relative to 07/150, overall percentage geometric coefficient of variation for A/Vietnam/1194/2004 was reduced from 125% to 61% for HI and from 183% to 81% for neutralization.

    Lack of reduced variability to clade 2 antigens suggested the need for clade-specific standards.

    Sheep antiserum as a standard did not reliably reduce variability.

    The World Health Organization has established 07/150 as an international standard for antibody to clade 1 subtype H5 and has an assigned potency of 1,000 IU/ampoule.