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Vaccine
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doi:10.1016/j.vaccine.2011.11.019 | How to Cite or Link Using DOI
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Reproducibility of serology assays for pandemic influenza H1N1: Collaborative study to evaluate a candidate WHO International Standard☆
John M. Wooda, 1, Diane Majora, Corresponding Author Contact Information, E-mail The Corresponding Author, Alan Heatha, Robert W. Newmana, Katja H?schlerb, Iain Stephensonc, Tristan Clarkc, Jacqueline M. Katzd, Maria C. Zambonb
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a National Institute for Biological Standards and Control, Health Protection Agency, Potters Bar, United Kingdom
b Centre for Infection, Health Protection Agency, Colindale, United Kingdom
c University of Leicester, Leicester, United Kingdom
d Centers for Disease Control and Prevention, Atlanta, GA, United States
Received 24 August 2011; revised 4 November 2011; Accepted 5 November 2011. Available online 17 November 2011.
Abstract
Haemagglutination?inhibition (HI) and virus neutralisation (VN) assays are used to evaluate immunogenicity of pandemic H1N1 vaccines; however these bioassays are poorly standardised leading to inter-laboratory variation. A candidate International Standard (IS) for antibody to H1N1pdm virus (09/194) was prepared from pooled sera of subjects who had either recovered from H1N1pdm infection or who had been immunised with an adjuvanted subunit vaccine prepared from reassortant virus NYMC X-179A (derived from A/California/7/2009 virus). Ten laboratories from seven countries tested the candidate IS, 09/194 and a panel of human sera by HI and VN using the A/California/7/2009 virus (six laboratories) and/or the reassortant virus NYMC X-179A (ten laboratories). As expected, the inter-laboratory variability for HI and VN assay results was high. For results of antibody tests to NYMC X-179A, the % geometric coefficient of variation (%GCV) for 09/194 between laboratories was 83% for HI and 192% for VN. For tests of all sera, the median %GCV ranged from 95 to 345% for HI (80-fold variation) and 204 to 383% for VN (109-fold variation), but for the titres relative to 09/194 the median %GCV was much reduced (HI 34?231%; VN 44?214%). For tests of antibody to the A/California/7/2009 wild type virus there were similar reductions in %GCV when 09/194 was used.
These results suggest that 09/194 will be of use to standardise assays of antibody to A/California/7/2009 vaccine and 09/194 has now been established by WHO as an IS for antibody to A/California/7/2009 with an assigned potency of 1300 IU per ml.
Highlights
► We evaluated the reproducibility of pandemic H1N1 influenza antibody assays. ► A candidate pandemic H1N1 antibody standard was assessed. ► Inter-laboratory variability was high but was reduced by use of the standard. ► The International Standard for pandemic H1N1 antibody has been established by WHO. ► There was no overall correlation between HI and VN titres.
http://www.sciencedirect.com/science/article/pii/S0264410X11017865
In Press, Uncorrected Proof - Note to users
doi:10.1016/j.vaccine.2011.11.019 | How to Cite or Link Using DOI
Permissions & Reprints
Reproducibility of serology assays for pandemic influenza H1N1: Collaborative study to evaluate a candidate WHO International Standard☆
John M. Wooda, 1, Diane Majora, Corresponding Author Contact Information, E-mail The Corresponding Author, Alan Heatha, Robert W. Newmana, Katja H?schlerb, Iain Stephensonc, Tristan Clarkc, Jacqueline M. Katzd, Maria C. Zambonb
Purchase
a National Institute for Biological Standards and Control, Health Protection Agency, Potters Bar, United Kingdom
b Centre for Infection, Health Protection Agency, Colindale, United Kingdom
c University of Leicester, Leicester, United Kingdom
d Centers for Disease Control and Prevention, Atlanta, GA, United States
Received 24 August 2011; revised 4 November 2011; Accepted 5 November 2011. Available online 17 November 2011.
Abstract
Haemagglutination?inhibition (HI) and virus neutralisation (VN) assays are used to evaluate immunogenicity of pandemic H1N1 vaccines; however these bioassays are poorly standardised leading to inter-laboratory variation. A candidate International Standard (IS) for antibody to H1N1pdm virus (09/194) was prepared from pooled sera of subjects who had either recovered from H1N1pdm infection or who had been immunised with an adjuvanted subunit vaccine prepared from reassortant virus NYMC X-179A (derived from A/California/7/2009 virus). Ten laboratories from seven countries tested the candidate IS, 09/194 and a panel of human sera by HI and VN using the A/California/7/2009 virus (six laboratories) and/or the reassortant virus NYMC X-179A (ten laboratories). As expected, the inter-laboratory variability for HI and VN assay results was high. For results of antibody tests to NYMC X-179A, the % geometric coefficient of variation (%GCV) for 09/194 between laboratories was 83% for HI and 192% for VN. For tests of all sera, the median %GCV ranged from 95 to 345% for HI (80-fold variation) and 204 to 383% for VN (109-fold variation), but for the titres relative to 09/194 the median %GCV was much reduced (HI 34?231%; VN 44?214%). For tests of antibody to the A/California/7/2009 wild type virus there were similar reductions in %GCV when 09/194 was used.
These results suggest that 09/194 will be of use to standardise assays of antibody to A/California/7/2009 vaccine and 09/194 has now been established by WHO as an IS for antibody to A/California/7/2009 with an assigned potency of 1300 IU per ml.
Highlights
► We evaluated the reproducibility of pandemic H1N1 influenza antibody assays. ► A candidate pandemic H1N1 antibody standard was assessed. ► Inter-laboratory variability was high but was reduced by use of the standard. ► The International Standard for pandemic H1N1 antibody has been established by WHO. ► There was no overall correlation between HI and VN titres.
http://www.sciencedirect.com/science/article/pii/S0264410X11017865