Viruses of Special Concern
A novel influenza A virus is one that has caused human infection, but is different from current seasonal human influenza A viruses spreading among people. Novel influenza A viruses can be viruses that originate in animals that gain the ability to infect humans or human viruses that change significantly so as to be different from current human seasonal influenza A viruses. Some novel flu A viruses are believed to pose a greater pandemic threat than others and are more concerning to public health officials because they have caused serious human illness and death and also have been able to spread in a limited manner from person-to-person. Novel influenza A viruses are of extra concern because of the potential impact they could have on public health if they gained the ability to spread from person-to-person easily, triggering a pandemic. The text below summarizes the novel influenza A viruses that are currently most concerning to public health officials.
Risk Assessment
CDC and non-CDC influenza experts have developed a tool that assesses the potential pandemic risk posed by novel influenza A viruses. Influenza Risk Assessment Tool results are summarized in a table.
- Page last reviewed: March 30, 2017
- Page last updated: March 30, 2017
- Content source:
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases (NCIRD)
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