<abstract xmlns="http://www.w3.org/1999/xhtml">

<sec id="j_jvetres-2019-0066_s_005">
<h3>Introduction</h3>
<p><italic>Riemerella anatipestifer</italic> (RA) infections can lead to high mortality in ducklings. Inactivated vaccines against RA are commercially available, but they fail to provide cross-protection against various serotypes. We have previously demonstrated that a subunit vaccine containing recombinant outer membrane protein A (rOmpA) antigen of serotype 2 formulated with CpG oligodeoxynucleotides (ODN) as the adjuvant was able to stimulate both humoral and cellular immunities.</p></sec>
<sec id="j_jvetres-2019-0066_s_006">
<h3>Material and Methods</h3>
<p>In the present study, thirty healthy 7-day-old Pekin ducks were randomly assigned to three equal treatment groups: rOmpA-vaccinated, rOmpA + CpG-vaccinated, and control. Vaccine was injected intramuscularly and a booster dose of the same vaccine was given two weeks after primary immunisation. The long-term antibody response and cross-serotype reaction of this vaccine were evaluated in ducks.</p></sec>
<sec id="j_jvetres-2019-0066_s_007">
<h3>Results</h3>
<p>Compared to ducks immunised with rOmpA alone, ducks immunised with rOmpA + CpG ODN had significantly (p &lt; 0.05) increased serum antibody titre from two weeks until nine months after primary immunisation. In addition, expression of cytokines including interferon (IFN)-α, IFN-γ, interleukin (IL)-6, and IL-12 was significantly (p &lt; 0.05) enhanced in PBMC of ducks immunised with rOmpA + CpG ODN two weeks after primary immunisation. Antibodies from ducks immunised with the rOmpA + CpG ODN vaccine could also detect RA serotypes 1 and 6 in Western blot analysis.</p></sec>
<sec id="j_jvetres-2019-0066_s_008">
<h3>Conclusion</h3>
<p>Combination of rOmpA and CpG ODN could be a feasible strategy for developing a subunit RA vaccine with long term and broader-ranging protection.</p></sec></abstract>

Introduction
Riemerella anatipestifer (RA) infections can lead to high mortality in ducklings. Inactivated vaccines against RA are commercially available, but they fail to provide cross-protection against various serotypes. We have previously demonstrated that a subunit vaccine containing recombinant outer membrane protein A (rOmpA) antigen of serotype 2 formulated with CpG oligodeoxynucleotides (ODN) as the adjuvant was able to stimulate both humoral and cellular immunities.

Material and Methods
In the present study, thirty healthy 7-day-old Pekin ducks were randomly assigned to three equal treatment groups: rOmpA-vaccinated, rOmpA + CpG-vaccinated, and control. Vaccine was injected intramuscularly and a booster dose of the same vaccine was given two weeks after primary immunisation. The long-term antibody response and cross-serotype reaction of this vaccine were evaluated in ducks.

Results
Compared to ducks immunised with rOmpA alone, ducks immunised with rOmpA + CpG ODN had significantly (p < 0.05) increased serum antibody titre from two weeks until nine months after primary immunisation. In addition, expression of cytokines including interferon (IFN)-α, IFN-γ, interleukin (IL)-6, and IL-12 was significantly (p < 0.05) enhanced in PBMC of ducks immunised with rOmpA + CpG ODN two weeks after primary immunisation. Antibodies from ducks immunised with the rOmpA + CpG ODN vaccine could also detect RA serotypes 1 and 6 in Western blot analysis.

Conclusion
Combination of rOmpA and CpG ODN could be a feasible strategy for developing a subunit RA vaccine with long term and broader-ranging protection.

Evaluation of long-term antibody response and cross-serotype reaction in ducks immunised with recombinant <italic>Riemerella anatipestifer</italic> outer membrane protein A and CpG ODN

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Evaluation of long-term antibody response and cross-serotype reaction in ducks immunised with recombinant  outer membrane protein A and CpG ODN

Introduction
Riemerella anatipestifer (RA) infections can lead to high mortality in ducklings. Inactivated vaccines against RA are commercially available, but...

Evaluation of long-term antibody response and cross-serotype reaction in ducks immunised with recombinant Riemerella anatipestifer outer membrane protein A and CpG ODN

Published Online: Nov 16, 2019

Page range: 543 - 548

Received: Apr 10, 2019

Accepted: Oct 24, 2019

DOI: https://doi.org/10.2478/jvetres-2019-0066

Keywords
duck, vaccine, adjuvant, long-term antibody

© 2019 M. Phonvisay et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Evaluation of long-term antibody response and cross-serotype reaction in ducks immunised with recombinant Riemerella anatipestifer outer membrane protein A and CpG ODN

Published Online: Nov 16, 2019

Page range: 543 - 548

Received: Apr 10, 2019

Accepted: Oct 24, 2019

DOI: https://doi.org/10.2478/jvetres-2019-0066

Keywordsduck, vaccine, adjuvant, long-term antibody

© 2019 M. Phonvisay et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
duck, vaccine, adjuvant, long-term antibody