2009 pandemic influenza: a review

A review of influenza is particularly relevant this year due to the ongoing novel H1N1 influenza pandemic.

Surveillance and clinical data including risk factors for infection and complications due to the current H1N1 pandemic are reviewed. New evidence on the safety of antiviral agents in children and studies on interventions to reduce community transmission of influenza are included. Influenza vaccine efficacy and improving immunization coverage have also been addressed by recent studies.

These studies from the early phase of the pandemic identify the population that are at high risk for complications, and affirm that active surveillance and prevention are important aspects of a public health response. Appropriate use of antiviral agents and improving influenza immunization coverage for all ages continue to be a challenge. Further studies are underway to improve the public health response, and the pandemic H1N1 strain is being incorporated into the 2010 seasonal influenza vaccine.