Comparison of autogenous and commercial H9N2 avian influenza vaccines in a challenge with recent dominant virus

Document Type : Full paper (Original article)


1 Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

2 Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

3 Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran

4 Department of Clinical Sciences, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran

5 Department of Animal Science, College of Agriculture and Natural Resources, Qaemshahr Branch, Islamic Azad University, Qaem Shahr, Iran


Background: Avian influenza (AI) caused by AI virus subtype H9N2 is a prevalent viral disease with enormous economic losses in poultry farms through significant respiratory and gastrointestinal manifestations. The degree of protection obtained from a vaccine strongly depends on the level of antigenic similarity between challenge and vaccine virus. Aims: The study aimed at investigating the possible effects of continuous antigenic changes occurring in circulating Iranian viruses since 1998 on the commercial vaccines outcome by using vaccine seeds from earlier outbreaks for inhibiting viral replication in target organs of broilers challenged with the recent isolate. Methods: Ninety broilers at one day of age were randomly allocated into 5 groups and vaccinated with autogenous or commercial vaccines (A or B). Two remaining groups consisted of challenged without vaccination and intact birds. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed on the trachea and faecal samples of challenged chickens with recent H9N2 virus to determine viral load. Moreover, humoral antibodies titers were evaluated by hemagglutination inhibition (HI) assay. Results: There was no significant difference in H9N2 viral load in the trachea among vaccinated groups on 5 days post challenge (DPC), but on 15 DPC, the autogenous vaccine significantly lowered viral load compared to commercial vaccines (P≤0.05). No significant differences in faecal swab’s viral load was observed between autogenous and commercial vaccine A, and both of them significantly inhibited viral load compared to unvaccinated group (P≤0.05). In addition, the autogenous vaccine elicited the highest HI titer. Conclusion: Inactivated vaccines that use isolates from previous outbreaks are no longer able to induce proper immunity against recent H9N2 viruses. It seems the time to change vaccine strains to more recent isolates that have better antigenic similarity with current circulating H9N2 viruses in the region has come.


Abdel-Moneim, AS; Afifi, MA and El-Kady, MF (2012). Isolation and mutation trend analysis of influenza A virus subtype H9N2 in Egypt. Virol. J., 9: 173.
Bashashati, M; Marandi, MV and Sabouri, F (2013). Genetic diversity of early (1998) and recent (2010) avian influenza H9N2 virus strains isolated from poultry in Iran. Arch. Virol., 158: 2089-2100.
Capua, I and Alexander, DJ (2008). Avian influenza vaccines and vaccination in birds. Vaccine. 26: 70-73.
Capua, I and Alexander, DJ (2009). Avian influenza and Newcastle disease: a field and laboratory manual. 1st Edn., Milan, Italy, Springer. PP: 85-89.
Choi, JG; Lee, YJ; Kim, YJ; Lee, EK; Jeong, OM; Sung, HW; Kim, JH and Kwon, JH (2008). An inactivated vaccine to control the current H9N2 low pathogenic avian influenza in Korea. J. Vet. Sci., 9: 67-74.
Ghafouri, SA; Langeroudi, AG; Maghsoudloo, H; Tehrani, F; Khaltabadifarahani, R; Abdollahi, H and Fallah, MH (2017). Phylogenetic study-based hemagglutinin (HA) gene of highly pathogenic avian influenza virus (H5N1) detected from backyard chickens in Iran, 2015. Virus Genes. 53: 117-120.
Ghalyanchi Langeroudi, A; Karimi, V; Kheiri, MT and Barin, A (2013). Full-length characterization and phylogenetic analysis of hemagglutinin gene of H9N2 virus isolated from broilers in Iran during 1998-2007. Comp. Clin. Pathol., 22: 321-330.
Gharaibeh, S and Amareen, S (2015). Vaccine efficacy against a new avian influenza (H9N2) field isolate from the Middle East (serology and challenge studies). Avian Dis., 59: 508-511.
Hosseini, H; Ghalyanchilangeroudi,A; Mehrabadi, MHF; Sediqian, MS; Shayeganmehr, A; Ghafouri, SA; Maghsoudloo, H; Abdollahi, H and Farahani, RK (2017). Phylogenetic analysis of H9N2 avian influenza viruses in Afghanistan (2016-2017). Arch. Virol., 162: 3161-3165.
Malekan, M; VasfiMarandi, M; Ranjbar, MM and Bashashati, M (2016). Molecular evaluation of M2 protein of Iranian avian influenza viruses of H9N2 subtype in order to find mutations of adamantane drug resistance. Iranian J. Vet. Med., 10: 253-262.
Medina, RA and García-Sastre, A (2011). Influenza A viruses: new research developments. Nat. Rev. Microbiol., 9: 590-603.
Moghaddam Pour, M; Momayez, R and Akhavizadegan, M (2006). The efficacy of inactivated oil-emulsion H9N2 avian influenza vaccine. Iran. J. Vet. Res., 7: 85-88.
Naeem, K and Siddique, N (2006). Use of strategic vaccination for the control of avian influenza in Pakistan. Dev. Biol. (Basel), 124: 145-150.
Nili, H and Asasi, K (2002). Natural cases and an experimental study of H9N2 avian influenza in commercial broiler chickens of Iran. Avian Pathol., 31: 247-252.
Pazani, J; Marandi, MV; Ashrafihelan, MJ; Marjanmehr, SH and Ghods, F (2008). Pathological studies of A/Chicken/Tehran/ZMT-173/99 (H9N2) influenza virus in commercial broiler chickens of Iran. Int. J. Poult. Sci., 7: 502-510.
Shayeganmehr, A; Vasfi Marandi, M; Karimi, V; Barin, A and Ghalyanchilangeroudi, A (2018). Zataria multiflora essential oil reduces replication rate of avian influenza virus (H9N2 subtype) in challenged broiler chicks. Br. Poult. Sci., 59: 389-395.
Suarez, D and Schultz-Cherry, S (2000). Immunology of avian influenza virus: a review. Dev. Comp. Immunol., 24: 269-283.
Sun, Y and Liu, J (2015). H9N2 influenza virus in China: a cause of concern. Protein Cell. 6: 18-25.
Swayne, DE (2006). Principles for vaccine protection in chickens and domestic waterfowl against avian influenza: emphasis on Asian H5N1 high pathogenicity avian influenza. Annals of the New York Academy of Sciences. 1081: 174-181.
Swayne, D; Beck, J; Garcia, M and Stone, H (1999). Influence of virus strain and antigen mass on efficacy of H5 avian influenza inactivated vaccines. Avian Pathol., 28: 245-255.
Swayne, DE and Kapczynski, D (2008). Strategies and challenges for eliciting immunity against avian influenza virus in birds. Immunol. Rev., 225: 314-331.
Vasfi Marandi, M and Bozorgmehri Fard, MH (2002). Isolation of H9N2 subtype of avian influenza viruses during an outbreak in chickens in Iran. Iran Biomed. J., 6: 13-17.