Influenza A (H1N1) 2009 reinfection in Thailand

SummaryIn 2009, a novel influenza A (H1N1) virus emerged and rapidly spread around the world, leading to a pandemic. In contrast to the high rate of primary infection, reinfection with influenza A (H1N1) 2009 is rather rare. In this report, we describe a case of influenza A (H1N1) 2009 reinfection that occurred within an interval of 5 months in Thailand.

► We describe a case of influenza A (H1N1) 2009 reinfection that occurred within an interval of 5 months in Thailand.
► Influenza A (H1N1) 2009 reinfection is possible; however, the severity of disease was significantly lower upon reinfection.
► Our finding suggests the possibility of a sub-optimal immune response that failed to provide protection after exposure to the first natural infection.