Journal: NPJ Vaccines

Article Title: A neuraminidase potency assay for quantitative assessment of neuraminidase in influenza vaccines

doi: 10.1038/s41541-019-0099-3

Figure Lengend Snippet: VaxArray Influenza Seasonal Neuraminidase Potency Assay (VXI-sNA). a Illustration of a VXI-sNA microarray slide containing 16 identical microarrays in 16 wells. b Schematic of the VXI-sNA array layout of subtype-specific antibodies to N1, N2 subtypes and B-NA. Two different monoclonal antibodies (mAbs) are printed for each subtype and distinguished from one another using (i) or (ii) labeling. The array contains nine replicate spots (~200 µm in diameter) of each monoclonal antibody. c Immunoassay schematic. d Qualitative assessment of VXI-sNA capture mAbs for detection of a panel of recent vaccine strains produced across multiple production platforms with a blue box and checkmark to indicate mAb detection of the listed antigen. Detection was defined as 3× the background intensity. e Signal intensities for each VXI-sNA capture mAb against a panel of historical FluZone vaccines from 2004 to 2012. White/empty boxes indicate signal intensity below the 3× background intensity cutoff, yellow indicates signal intensity between 3× and 20× background intensity, green indicates between 20×–40× background, and blue indicates between 40× and fluorescence saturation

Article Snippet: Samples were labeled with the NA A&B pAb Label (InDevR, Cat # 7616) and imaged using the VaxArray Imaging System and Software.

Techniques: Potency Assay, Microarray, Labeling, Produced, Fluorescence

Journal: NPJ Vaccines

Article Title: A neuraminidase potency assay for quantitative assessment of neuraminidase in influenza vaccines

doi: 10.1038/s41541-019-0099-3

Figure Lengend Snippet: Linear dynamic range comparison of VaxArray Influenza Seasonal NA Potency Assay (VXI-sNA) and a neuraminidase (NA) activity assay. Serial dilutions of four antigens were analyzed by VXI-sNA and an NA activity assay. VXI-sNA response curves, enzymatic activity response curves, and a correlation plot of one of the VXI-sNA capture antibody vs. NA activity are shown, respectively, for H1N1 A/California (CBER, Lot # 76) ( a – c ), H3N2 A/Hong Kong (CBER, Lot # 84) ( d – f ), B/Brisbane (CBER, Lot # 77) ( g – i ), and B/Phuket/3073/2013 (CBER, Lot # 90) ( j – l ). For correlation plots ( c , f , i , l ), the signal responses for N1(i), N2(i), and NB(i) are plotted against the corresponding activity response. Error bars for VXI-sNA represent the standard deviation of the nine antibody spots for the corresponding capture antibody for each array. Error bars for the enzymatic activity represent previously determined representative error of the assay (2.5%)

Article Snippet: Samples were labeled with the NA A&B pAb Label (InDevR, Cat # 7616) and imaged using the VaxArray Imaging System and Software.

Techniques: Potency Assay, Activity Assay, Standard Deviation

Journal: NPJ Vaccines

Article Title: A neuraminidase potency assay for quantitative assessment of neuraminidase in influenza vaccines

doi: 10.1038/s41541-019-0099-3

Figure Lengend Snippet: Precision. A trivalent mixture of H1N1 A/California (CBER, Lot # 76), H3N2 A/Hong Kong (CBER, Lot # 84), and B/Phuket (CBER, Lot # 80) antigen was diluted to three concentrations and analyzed in eight replicates against a standard curve generated from the same trivalent mixture. All concentrations were normalized to the N1 concentration. The experiment was performed by three separate users, on three separate days, with three separate reagent lots, represented by the three different colored points in a . The average neuraminidase (NA) concentration of all 24 replicates across all 3 days for each antibody is shown as a thick black bar. Error bars represent the standard deviation of all 24 replicates. b The relative standard deviation (RSD) is shown for various comparisons, including the high-, medium-, and low-concentration samples, the overall day-to-day variability, and the overall variability including scanning the same slides using different VaxArray Imaging Systems

Article Snippet: Samples were labeled with the NA A&B pAb Label (InDevR, Cat # 7616) and imaged using the VaxArray Imaging System and Software.

Techniques: Generated, Concentration Assay, Standard Deviation, Imaging

Journal: NPJ Vaccines

Article Title: A neuraminidase potency assay for quantitative assessment of neuraminidase in influenza vaccines

doi: 10.1038/s41541-019-0099-3

Figure Lengend Snippet: VaxArray Influenza Seasonal NA Potency Assay (VXI-sNA) and neuraminidase (NA) activity assay response to thermally degraded antigen. A B/Phuket sample (CBER, Lot # 80) was incubated at 45 °C for up to 10 h. After degradation, each time point was analyzed by VXI-sNA and an NA activity assay and the NA concentration and activity measured in replicate of three. The average %T0 (assay response at the time point divided by the T0, non-degraded, sample response) is plotted for each time point for the NB(i) monoclonal antibody (mAb) (blue curve), NB(ii) mAb (orange curve), and NA activity assay (gray curve). Error bars represent the standard deviation of the triplicate measurements of each time point

Article Snippet: Samples were labeled with the NA A&B pAb Label (InDevR, Cat # 7616) and imaged using the VaxArray Imaging System and Software.

Techniques: Potency Assay, Activity Assay, Incubation, Concentration Assay, Standard Deviation

Journal: NPJ Vaccines

Article Title: A neuraminidase potency assay for quantitative assessment of neuraminidase in influenza vaccines

doi: 10.1038/s41541-019-0099-3

Figure Lengend Snippet: Quantification of neuraminidase (NA) by VaxArray Influenza Seasonal NA Potency Assay (VXI-sNA) in the presence of common interfering agents. The following antigens were spiked into phosphate-buffered saline (PBS), allantoic fluid, 40% sucrose, and exhausted Dulbecco’s modified Eagle’s medium (DMEM) + 10% fetal bovine serum (FBS) medium from uninfected Madin–Darby Canine Kidney (MDCK) cells (tissue culture media) to a final concentration of 2 µg/mL and then analyzed by VXI-sNA: H1N1 A/California (CBER, Lot # 76), H3N2 A/Hong Kong (CBER, Lot # 84), and B/Phuket (CBER, Lot # 80). The VXI-sNA measurements for each capture antibody were then divided by the expected concentration of 2 µg/mL and multiplied by 100 to generate “% Expected Concentrations” that were then plotted individually for each replicate a . VXI-sNA potency determination for influenza antigens spiked into common adjuvants such as aluminum hydroxide (alum) and MF59 is shown in b . For each sample, a PBS-negative control was included. For both a and b each data point represents a single replicate. The thick black bar represents the average across the four replicates. Error bars represent the standard deviation across the four replicates for each sample. The red-dotted line represents the 100% expected concentration for each sample. The shaded red region represents 100% expected concentration plus and minus 10% for a and 5% for b

Article Snippet: Samples were labeled with the NA A&B pAb Label (InDevR, Cat # 7616) and imaged using the VaxArray Imaging System and Software.

Techniques: Potency Assay, Modification, Concentration Assay, Negative Control, Standard Deviation