Resumen del trabajo presentado al XII Congreso Nacional de Virología de la Sociedad Española de Virología (SEV), celebrado en Burgos del 9 al 12 de junio de 2013.-- et al. ; West Nile virus (WNV), a neurovirulent Flavivirus, is maintained in nature in an enzootic transmission cycle between avian hosts and mosquito vectors, although the virus occasionally infects other vertebrates, including humans, in which it may result fatal. In Europe the virus has been present for decades but, recently, the number, frequency and severity of outbreaks have increased dramatically. To date, no licensed vaccines against WNV infection are available for bird usage. Although the cost-effectiveness of generalized vaccination programs is uncertain, the availability of WNV vaccines would certainly benefit specific populations, including birds grown for restocking, hunting activities, or alimentary purposes, and those confined to wildlife reservations, zoos, or other recreation installations. Here, we have tested the protective capability of WNV enveloped recombinant (rE) protein in red-legged partridges (Alectoris rufa), a gallinaceous bird widely distributed in South and Western Europe and intensively breed for hunting purposes. Partridges were intramuscularly immunized three times at 2-weeks interval with 10 mg/bird of partially purified rE protein plus adjuvant. An additional control group was sham-immunized before challenge. Except for 5 birds that were non-challenged and housed as contact controls, all birds were subcutaneously infected with 107 PFU of the highly neurovirulent NY99 WNV strain at our BSL-3 facilities. Oropharyngeal and cloacal swabs and feather pulp samples were collected daily up to 14 days post-infection, d.p.i. Birds were bled one week before the first immunization and at several time points during vaccination and after infection. While none of the sham-immunized birds showed anti-WNV Ab, all rE-vaccinated birds presented specific Ab after two immunizations, and most of them had nAb before challenge. Accordingly, none of the rE vaccinated partridges died, while 33.3% of the PBS-inoculated birds succumbed to the infection, as did 25% of the contact animals. Except one, all unvaccinated birds showed viremia by 3 d.p.i., being generally higher in partridges that died of WN disease. In contrast only 3 rE vaccinated birds showed viremia with very low titers. Preliminary data indicate that WNV-RNA could be detected in feathers and swabs from PBS inoculated partridges from 3 to 7 d.p.i., but not in those from rE vaccinated birds. Thus, rE vaccination fully protected partridges against WND and reduced the risk of virus spread. ; Peer Reviewed