The emergence of the drug-resistant Influenza A strains including the antiviral resistant 2009 pandemic H1N1 (pH1N1) highlighted this urgent need to develop new antiviral strategies for protecting against infection of Influenza virus. Type I interferon including interferon alpha and beta (IFN-α/β) produced by host cells in response to the presence of pathogens, plays a critical role in viral pathogen clearance during infection. In this study we determined the effect of Alferon N Injection® (a natural interferon alpha product derived from human leukocytes, IFN-α-n3) on the Influenza A virus including pH1N1 virus isolated from pigs, Avian H9N2 and Swine H3N2 viruses in human alveolar epithelial A549 cells. The results showed that IFN-α-n3 is able to inhibit replication of these three Influenza A viruses in human alveolar epithelial cells, indicating that IFN-α-n3 may be useful in treating Influenza clinically.

Although the 2009 flu pandemic did not cause the high mortality rates as predicated in June, 2009 when the world health organization (WHO) declared the first pandemic in 41 years, the outbreak reminded us that ,nfluenza remains a major infectious disease and public health challenge. Нis outbreak reinforced the problems of vaccine production capacity and supply in response to a pandemic. For example, no pandemic H1N1 vaccine was available in most developing countries even more than 8 months aÑ–er the WHO declared the pandemic To examine the eوٴect of IFN-α-n3 on the pH1N1, Avian H9N2 and Swine H3N2 virus replication, we studied diوٴerent concentrations of IFN-α-n3 treating human alveolar epithelial A549 cells (ATCC, CCL-185) which were then infected with respective viruses at the indicted multiplicity of infection (MOI), respectively. A Swine-origin pH1N1 (A/Swine/Alberta/25/2009, Alb09) virus was kindly provided by Dr. Webby at St. Jude Children's Research Hospital and used in this study which was isolated from the Canadian pigs and the genome of this virus exhibited 99.6%-100% identity at nucleotide acid level with that of the human isolate (A/CA/04/09, CA09). We have shown that both Alb09 and CA09 pH1N1 viruses are highly pathogenic and transmissible in pigs . An Avian H9N2 A/Quail/Hong Kong/ G1/1997 (HK97) generated by reverse genetics  and an H3N2 triple reassortant A/Swine/Texas/4199-2/98 virus (TX98), which was obtained from the repository at St. Jude Children's Research Hospital, Memphis, Tennessee were utilized in this study; the HK97 virus is genetically and antigenically similar to an H9N2 virus which infected humans in 1999