The 2009 pandemic influenza H1N1 (pdmH1N1) is characterized by rapid transmission among humans and disproportionate infection to children and young adults. Although the pdmH1N1 demonstrated less lethality than initially expected and has now moved into its post-pandemic period, it remains highly possible that through antigenic shift or antigenic drift the pdmH1N1 might re-emerge in the future as a more virulent strain than before, underscoring the need for vaccination prior to an outbreak. Using X-31 ca as a backbone strain, we generated a live attenuated pdmH1N1 vaccine and evaluated its potential as a safe and effective vaccine using mouse and ferret models. Despite an acceptable level of attenuation phenotypes, single dose of immunization with the vaccine efficiently stimulated both systemic and mucosal antibody responses and provided complete protection against lethal challenge with wild type pdmH1N1 virus, even at the lowest immunization dose of 103PFU. The promising results of safety, immunogenicity, and protective efficacy of the vaccine not only contribute to expanding the repertoire of live vaccines as a judicious choice for pandemic H1N1 preparedness, but also suggest the great potential of X-31 ca donor strain to serve as reliable platform for generating diverse live vaccine constructs against seasonal influenza viruses and other pandemic strains.
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Conflict of interest statement: The authors declare no conflicts of financial interests. Role of the funding source: This work was supported by the R&D Program of Ministry of Knowledge Economy [grant number 10031969 ] and Ministry of Education, Science, and Technology [grant number 2010-0001932 ] of Korean Government. This study was also supported in part by a grant from the Korea CDC [grant number 2009-E0066800 ] and a grant from the Korea Healthcare Technology R&D project by Korean Government [grant number A085105 ]. The funding source did not have roles in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication.
All Science Journal Classification (ASJC) codes
- Molecular Medicine
- Immunology and Microbiology(all)
- Public Health, Environmental and Occupational Health
- Infectious Diseases