Learn More
Pandemic influenza requires interspecies transmission of an influenza virus with a novel hemagglutinin (HA) subtytpe that can adapt to its new host through either reassortment or point mutations and transmit by aerosolized respiratory droplets. Two previous pandemics of 1957 and 1968 resulted from the reassortment of low pathogenic avian viruses and human(More)
The events and mechanisms that lead to interspecies transmission of, and host adaptation to, influenza A virus are unknown; however, both surface and internal proteins have been implicated. Our previous report highlighted the role that Japanese quail play as an intermediate host, expanding the host range of a mallard H2N2 virus, A/mallard/Potsdam/178-4/83(More)
H9N2 avian influenza A viruses are endemic in poultry of many Eurasian countries and have caused repeated human infections in Asia since 1998. To evaluate the potential threat of H9N2 viruses to humans, we investigated the replication and transmission efficiency of H9N2 viruses in the ferret model. Five wild-type (WT) H9N2 viruses, isolated from different(More)
A novel, swine-origin influenza H1N1 virus (H1N1pdm) caused the first pandemic of the 21st century. This pandemic, although efficient in transmission, is mild in virulence. This atypical mild pandemic season has raised concerns regarding the potential of this virus to acquire additional virulence markers either through further adaptation or possibly by(More)
IgG was traditionally thought to neutralize virions by blocking their attachment to or penetration into mucosal epithelial cells, a common site of exposure to viruses. However, we describe an intracellular neutralizing action for an influenza hemagglutinin-specific monoclonal antibody, Y8-10C2 (Y8), which has neutralizing activity only at an acidic pH. When(More)
Infectious pancreatic necrosis viruses (IPNVs) exhibit a wide range of virulence in salmonid species. In previous studies, we have shown that the amino acid residues at positions 217 and 221 in VP2 are implicated in virulence. To pinpoint the molecular determinants of virulence in IPNV, we generated recombinant IPNV strains using the cRNA-based(More)
Avian influenza (AI) viruses have been sporadically isolated in South America. The most recent reports are from an outbreak in commercial poultry in Chile in 2002 and its putative ancestor from a wild bird in Bolivia in 2001. Extensive surveillance in wild birds was carried out in Argentina during 2006-2007. Using RRT-PCR, 12 AI positive detections were(More)
Highly pathogenic avian H5N1 influenza viruses are endemic in poultry in Asia and pose a pandemic threat to humans. Since the deployment of vaccines against a pandemic strain may take several months, adequate antiviral alternatives are needed to minimize the effects and the spread of the disease. Passive immunotherapy is regarded as a viable alternative.(More)
The influenza A/Mallard/Pennsylvania/10218/1984 (H5N2) virus is unable to replicate in 3-wk-old immunocompetent specific-pathogen-free chickens when a dose of 5 x 10(6) 50% egg infectious dose/ml is used. In contrast, this mallard virus shows limited replication in 3-wk-old chickens that had been previously infected at 2 days of age with, and recovered(More)
In light of the recurrent outbreaks of low pathogenic avian influenza (LPAI) and highly pathogenic avian influenza (HPAI), there is a pressing need for the development of vaccines that allow rapid mass vaccination. In this study, we introduced by reverse genetics temperature-sensitive mutations in the PB1 and PB2 genes of an avian influenza virus, A/Guinea(More)