2009 H1N1 influenza pandemic

The 2009 H1N1 influenza pandemic took health care workers worldwide by surprise. Early in the course of the pandemic it was determined that children and pregnant women were at high risk of increased morbidity and mortality from the novel influenza virus. The Centers for Disease Control and Prevention and state and local public health officials quickly rallied to develop treatment guidelines for the new strain of influenza A, including emergency approvals for off-label use of some antiviral drugs. Prevention of the spread of influenza via vaccination and environmental controls is critical to the health of children. The 2009 H1N1 influenza virus emerged too late to be included in the 2009/2010 seasonal influenza vaccine, so production of a monovalent vaccine was set in motion. Five months from when the first cases of novel H1N1 appeared in Mexico and the United States, a vaccine was being distributed to high-risk patients. Looking ahead to the 2010/2011 influenza season, it is difficult to predict 2009 H1N1 activity. The 2010/2011 seasonal influenza vaccine will include the 2009 H1N1 strain, so it is critical to get all children vaccinated early in the flu season.