Transmission of highly pathogenic avian influenza H5N1 virus in Pekin ducks is significantly reduced by a genetically distant H5N2 vaccine

Abstract

Domestic ducks play an important role in the epidemiology of H5N1 avian influenza. Although it is known that vaccines that have a high homology with the challenge virus are able to prevent infection in ducks, little is yet known about the ability of genetically more distant vaccines in preventing infection, disease, and transmission. Here we study the effect of a widely used H5N2 vaccine (A/Chicken/Mexico/232/94/CPA) on the transmission of H5N1 virus (A/Chicken/China/1204/04) in ducks. The quantitative analyses show that despite the low level of homology between the virus and vaccine strain transmission was significantly reduced two weeks after a single or double vaccination. Mortality and disease rates were reduced markedly already one week after a single vaccination.

Species-Specific Contribution of the Four C-Terminal Amino Acids of Influenza A Virus NS1 Protein to Virulence

“…Being excreted longer possibly means that the virus can contaminate more individuals. Valuable information would certainly be obtained by evaluating the transmissibility of the ESEV and RSKV viruses in ducks (35,43,49) and in a suitable mammalian model, such as the ferret (18,41). Finally, viral sequence analysis after rounds of natural interhost transmission could enable the evaluation of the mutation rate of the sequence encoding the C-terminal domain of NS1.…”

Controlling highly pathogenic avian influenza outbreaks: An epidemiological and economic model analysis

“…Parameter values for turkeys and ducks are assumed to be identical to the parameter values for chickens, as the parameter value variability for different host species and virus strains is comparable. Detection of HPAI by observed mortality in duck flocks is expected to be lower ( Van der Goot et al, 2008), but this is counteracted by targeted clinical examination and serological screening during the epidemic (Anon, 2007). So, even though the small numbers of turkey and duck farms can play an important role during the silent spread phase, the numerous chicken farms are thought to drive the epidemic during the control phase of the epidemic.…”

Nucleocapsid of rabies virus improve immune response of an inactivated avian influenza vaccine

“…This kind of vaccine has been used in control programs for avian influenza in chickens in Mexico, where its efficacy has been shown since 1995 (Villareal and Flores 1997), and even in other species (Van der Goot et al 2008;Swayne and Kapczynski 2008). A strong anamnestic response was consistently observed after challenge.…”