Avian Influenza Vaccines

Two types of vaccines against avian influenza are available:

1. Conventional vaccines 
   • Inactivated oil emulsion vaccines that are used worldwide.
   • May be homologous or heterologous
   • Infection in a vaccinated flock can be monitored through the use of sentinel birds or serology (heterologous vaccines). Read more in Monitoring.
     
     
2. Recombinant vaccines  
   • Vectors used are ILT or Fowl Pox
   • Not licensed in the EU
   • Still used in Mexico
   • Have the potential to be used as “marker” vaccines 

Heterologous Avian Influenza Vaccines

The influenza A vaccine strain in a heterologous vaccine contains the same haemagglutinin (H) sub-type as the field virus but a different neuraminidase (N).

Protection by H sub-type
Experimental data has shown that vaccinated birds are protected from avian influenza infection provided that the vaccine strain H subtype is the same as that of the field infection.

For more information see:

• D. E. Swayne, J. R. Beck, M. Garcia, H. D. Stone
  Influence of virus strain and antigen mass on efficacy of H5 avian influenza inactivated vaccines
  Avian Pathology, 28, 245-255
  Abstract
  
  
• Ming Liu, John M. Wood, Trevor Ellis, Scott Krauss, Patrick Seiler, Christie Johnson, Erich Hoffmann, Jennifer Humberd, Diane Hulse, Yun Zhang, Robert G. Webster and Daniel R. Perez
  Preparation of a standardized, efficacious agricultural H5N3 vaccine by reverse genetics.
  Virology, Volume 314, Issue 2, 30 September 2003, Pages 580-590
  Abstract 

For Information on Intervet Influenza vaccines, see Products.