About

The 2018 pandemic H7N9 virus is a novel influenza A(H7N9) virus of bird origin that has adapted to infect and spread easily between people and is causing a pandemic at this time. The virus originated in China. A predecessor to the current pandemic H7N9 virus was first identified in people in 2013, causing rare sporadic poultry-to-human infections between 2013 and the present time. The pandemic H7N9 virus was first detected on August 4, 2018. The 2018 pandemic H7N9 virus is causing increasing numbers of illnesses, hospitalizations and deaths in the United States. An increasing number of cases are being reported internationally as well. It’s thought that 2018 H7N9 virus spreads in the same way that seasonal influenza viruses spread; mainly through the coughs and sneezes of people who are sick with the virus to others in close proximity.

While we still have much to learn about this pandemic virus, preliminary data indicate it is associated with serious illness and high levels of mortality. Because this is a new virus, most people will not have immunity to it, and illness may be more severe and widespread as a result.

The virus is susceptible to the influenza antiviral drugs, oseltamivir, zanamivir and peramivir.

The federal government produced and stockpiled H7N9 pre-pandemic vaccine. The current pandemic H7N9 virus is antigenically different from pre-pandemic H7N9 vaccines developed in 2013 and 2017, but stockpiled H7N9 vaccines can be used for a first dose to prime the immune system, to be followed by a dose of the new 2018 H7N9 pandemic vaccine when it is available. The process to develop and produce 2018 H7N9 pandemic vaccine has begun, but significant doses of this vaccine will not be available for some months. Once available, CDC will prioritize availability of stockpiled H7N9 vaccine based on risk and occupation criteria. In the meantime, the public health response is reliant on the judicious use of antiviral medications for treatment and a combined set of recommendations around non-pharmaceutical interventions to help slow the spread of disease.

CDC anticipates that there will be more cases, more hospitalizations and more deaths associated with this new virus in the coming days and weeks.

Epidemiology

Most human infections with avian influenza viruses, including Asian H7N9 virus, occur after exposure to infected poultry or contaminated environments. Asian H7N9 viruses continue to circulate in poultry in China. Most reported patients with H7N9 virus infection have had severe respiratory illness (e.g., pneumonia).