en تخصصي Special گزارش کوتاه Short communication <div style="border-bottom:solid windowtext 1.0pt; border-top:solid windowtext 1.0pt; border-left:none; border-right:none; padding:1.0pt 0in 1.0pt 0in"><span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:10.5pt">Background and Aims: </span></b><span style="font-size:10.5pt">Ostriches (Struthio camelus) exhibit marked susceptibility to avian influenza viruses (AIV), particularly H5 subtypes, posing substantial economic risks to global ostrich farming operations. This study evaluated the immunogenicity of an inactivated H5 influenza vaccine (Re-6+Re-8) in Iranian ostriches using hemagglutination inhibition (HI) assays.</span></span></span></span><br> <span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:10.5pt">Material and methods:</span></b><span style="font-size:10.5pt"> We conducted a comparative serological analysis of 30 vaccinated (three-dose regimen) and 30 unvaccinated adult ostriches across two major farming provinces.</span></span></span></span><br> <span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:10.5pt">Results:</span></b><span style="font-size:10.5pt"> Vaccinated birds demonstrated significantly higher HI titers (3.1 &plusmn; 0.8 log₂) compared to unvaccinated controls (2.3 &plusmn; 0.74 log₂; p < 0.05), indicating vaccine-induced seroconversion. However, the modest antibody response fell below protective thresholds established for Galliformes, revealing suboptimal immunogenicity and considerable inter-individual variability.</span></span></span></span><br> <span style="font-size:12pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:10.5pt">Conclusions:</span></b><span style="font-size:10.5pt"> These findings highlight fundamental differences in immune responses between ostriches and conventional poultry species, emphasizing the urgent need for optimized vaccination protocols and enhanced biosecurity measures in ostrich farming systems.</span></span></span></span></div> Ostrich, H5 Avian Influenza, Vaccine Immunogenicity, Hemagglutination Inhibition 30 33 http://journal.isv.org.ir/browse.php?a_code=A-10-380-1&slc_lang=en&sid=1 Arash Ghalyanchilangeroudi arashghalyanchi@gmail.com 10031947532846008001 10031947532846008001 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Noorolah Nikkhah nikhahnoor@yahoo.com 10031947532846008002 10031947532846008002 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Zahra Ziafati Kafi zahra.ziafati@gmail.com 10031947532846008003 10031947532846008003 Yes Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Mohsen Mahmoodzadeh jahani_54@yahoo.com 10031947532846008004 10031947532846008004 No Department of Avian Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran. Fahime Jamiri f.jamiri@gmail.com 10031947532846008005 10031947532846008005 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Alireza Bakhshi arbakhshi.dvm@gmail.com 10031947532846008006 10031947532846008006 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Hassein Hosseini hosseini.ho@gmail.com 10031947532846008007 10031947532846008007 No Department of Avian Diseases, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Alborz, Iran. Rima Morshed dr_morshed2001@yahoo.com 10031947532846008008 10031947532846008008 No Agriculture and Veterinary Group, Faculty of encyclopedia, IHCS, Tehran, Iran. Mohammad Abdoshah m.abdoshah@rvsri.ir 10031947532846008009 10031947532846008009 No Department of Avian Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran. Mohammad Hossein Fallah Mehrabadi 10031947532846008010 10031947532846008010 No Department of Avian Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran. Soroush Sarmadi s.soroush2@gmail.com 10031947532846008011 10031947532846008011 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Ghazal Daghayeghi ghazaldaghayeghiesmaili@gmail.com 10031947532846008012 10031947532846008012 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Amitis Sedighi A.sedighi@gmail.com 10031947532846008013 10031947532846008013 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Mahtab Heydarpour m.heydarpoor@gmail.com 10031947532846008014 10031947532846008014 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Mani Mehrnia mmeh@gmail.com 10031947532846008015 10031947532846008015 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Seyad Alireza Rezaee sareza@gmail.com 10031947532846008016 10031947532846008016 No Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.