The first influenza pandemic of the 21st century that originated in swine in Mexico
in April 2009 exemplified the importance of recombinant technology for vaccine development
for both humans and lower animals. The pandemic 2009 H1N1 virus spread globally in
humans in a remarkably short time and has a wide zoonotic host range including swine,
turkeys, ferrets, cats and dogs. There was urgent need for rapid vaccine production
of both inactivated and live attenuated influenza vaccines that replicated well in
embryonated chicken eggs and cell cultures. Reverse genetics and conventional reassortment
were used to generate high yielding vaccine strains. Other strategies for rapidly
producing H1N1 vaccines included in vitro expression of the hemagglutinin in baculovirus.
While approved influenza vaccines for humans currently include only inactivated whole
virus, subunit and live attenuated vaccines many recombinant strategies are undergoing
development and some of these are approved for use in poultry.
Vaccines for animals including domestic poultry have been developed for the highly
pathogenic (HP) H5N1 avian influenza virus “bird flu” that is a threat to both human
and veterinary public health, particularly in multiple epicenters in Eurasia.
1 - Vaccines, Vaccination, and Immunology for Avian Influenza viruses in Poultry”
By Swayne DE and Kapczynski DR in Avian Influenza, edited by Swayne, DE. Blackwell
2 - Capua I, Alexander DJ. Vaccine. Avian influenza vaccines and vaccination in birds.
2008; 26 Suppl 4:D70-3.
3 - Kim JK, Kayali G, Walker D, Forrest HL, Ellebedy AH, Griffin YS, Rubrum A, Bahgat
MM, Kutkat MA, Ali MA, Aldridge JR, Negovetich NJ, Krauss S, Webby RJ, Webster RG.
Puzzling inefficiency of H5N1 influenza vaccines in Egyptian poultry. Proc Natl Acad
Sci U S A. 2010;107(24):11044-9.
The strategies for vaccine development and use have been widely used in China, Vietnam,
Indonesia and Egypt. The strategies include: 1)Inactivated Oil Emulsion Vaccines,
2) In vitro expression systems including i) baculovirus in insect culture, ii)Vaccinia,
iii) Adenovirus, iv) Alphavirus: virus like replicon particles, 3) In vivo expression
systems including i) Live attenuated influenza virus, ii) Fowl pox, iii) Avian leukosis
virus, iv) Paramyxovirus type 1 vectored, v) Gallid herpesvirus-1 and 4) DNA vaccines-Naked
In this presentation I will deal with some of the successes and failures of vaccine
use for controlling HP H5N1 influenza virus in poultry in Asia and Egypt. Additionally
the problems of poor immunogenicity of H5N1 vaccines in mammals including humans
and the need for modern adjuvants will be discussed.