NDV- and HPAIV-specific serum antibody responses following immunization with rNDV-HA and rNDV-HAF and survival of chickens after homologous and heterologous HPAIV challenge.

1<p>Chickens in groups of 5 or 10, as indicated, were vaccinated on day 0 with wtNDV, rNDV-HA, or rNDV-HAF. On day 21, serum samples were taken and the birds were challenged with 100 CLD₅₀ of the indicated HPAIV. Groups are named according to the immunizing NDV vector and the HPAIV strain used in the HI assays and challenge. Viet = homologous A/Vietnam/1203/2004; Egypt = heterologous A/Egret/Egypt/01/2006.</p>2<p>Mean of the viruses in #1 and #2.</p

Immunoelectron microscopy of purified virions of rNDV, rNDV-HA and rNDV-HAF, analyzed using mouse monoclonal antibodies against the NDV HN protein (upper panel) or chicken polyclonal antibodies against H5N1 AIV (lower panel).

<p>Immunoelectron microscopy of purified virions of rNDV, rNDV-HA and rNDV-HAF, analyzed using mouse monoclonal antibodies against the NDV HN protein (upper panel) or chicken polyclonal antibodies against H5N1 AIV (lower panel).</p

Frequency of shedding of the NDV-based vaccine viruses and HPAIV challenge viruses¹.

1<p>From the experiment in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006509#pone-0006509-t002" target="_blank">Table 2</a>. Shedding was determined by collecting oral and cloacal swabs on 3 day post vaccination and 3 day post challenge and inoculation into embryonated chicken eggs followed by HA tests for virus growth.</p

Comparison of pre-challenge (day 21) and post-challenge (day 31) NDV- and HPAIV-specific serum antibody titers¹.

1<p>Continuation of the experiment in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006509#pone-0006509-t002" target="_blank">Tables 2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006509#pone-0006509-t003" target="_blank">3</a>.</p>2<p>Viet = A/Vietnam/1203/2004; Egypt = A/Egret/Egypt/01/2006.</p>2a<p>Commercial NDV ELISA assay (Synbiotic Corporation, San Diego, CA).</p>3<p>The challenge virus was used for the HI antibody assays.</p>4<p>Commercial HPAIV NP ELISA assay (Synbiotic Corporation, San Diego, CA). Negative control OD = 0.083 and Positive control OD = 0.867.</p

Multicycle growth kinetics (A) and plaque morphology (B) of the rNDV, rNDV-HA and rNDV-HAF viruses in DF-1 cells.

<p>Multicycle growth kinetics (A) and plaque morphology (B) of the rNDV, rNDV-HA and rNDV-HAF viruses in DF-1 cells.</p