The 2009 H1N1 Pandemic

Old and New Challenges

In April 2009, a novel influenza A(H1N1) virus was detected in California that would later be called “influenza A(H1N1)pdm09.” In the early days of the outbreak, CDC faced familiar challenges, such as developing a laboratory diagnostic test kit to detect the new virus; getting FDA to authorize its use via an emergency use authorization (EUA); and distributing the kit nationwide to select state and local laboratories via the Influenza Reagent Resource (IRR). The kit was also distributed internationally to global public health laboratories. Other challenges included quickly developing a candidate vaccine virus¹ to provide to vaccine manufacturers; coordinating the national and international response; and informing the public during an evolving and uncertain situation.

However, the first influenza pandemic of the 21^st century brought new challenges as well. Through technological advances, the world had become highly interconnected. Information and misinformation about the pandemic could reach a wide audience faster than ever before, making the task of informing the public particularly challenging.