Abstract: Vaccines that would be recommended and offered in response to a novel influenza virus bring many communication challenges. This chapter identifies and describes some of the major issues that public health agencies and regulatory bodies, vaccine manufacturers, and healthcare professionals would face when it comes to pandemic influenza vaccines and immunization recommendations. It does so by drawing upon experiences, findings, and outcomes from the H1N1A influenza pandemic in 2009 that affected much of the world as well as lessons learned from annual influenza prevention efforts. It begins with challenges due to uncertainties and complexities brought by influenza viruses and then highlights experiences from different countries with a focus on France as a relevant example, illustrating the similarities and differences that can affect pandemic influenza vaccine communication. The final section of the chapter reflects on some key communication-related research findings as well as lessons learnt that can help guide those doing vaccination-related communication responses and efforts in future influenza pandemics.